Diseases and Disorders

Definition

• Acanthosis nigricans (AN) refers to the presence of symmetrical, brown, velvety, or verrucous plaques with a predilection for intertriginous sites, including the back of the neck, groin, and axillae ( Fig. 3.1 ).

  

Etiology

• It is most commonly seen in obese individuals with insulin resistance or an internal malignancy and in those taking certain medications (nicotinic acid, glucocorticoids, contraceptives, and diethylstilbestrol).

Clinical Manifestation(s)

• Asymptomatic. The axilla and neck are the most commonly involved. In obese females who are hyperandrogenic, the vulva is the most commonly affected site.

Physical Examination

• Symmetrical hyperpigmented velvety plaques of the major flexures (axilla, groin), neck ( Fig. 3.2 ) , nipples, and vulva.

  

Diagnostic Tests

• Laboratory evaluation often reveals elevated glucose levels. Additional useful laboratory tests are thyroid-stimulating hormone (TSH) and follicle-stimulating hormone (FSH)/luteinizing hormone (LH).

First Line

• Therapy for underlying cause (weight loss in obese, discontinuation of offending drugs, treatment of malignancy if present)

Second Line

• Topical tretinoin, dermabrasion, ammonium lactate, carbon dioxide ablative laser

Third Line

• Oral contraceptives, cyproheptadine, oral isotretinoin

Definition

• Acne keloidalis is an idiopathic chronic inflammatory eruption of the nape of the neck occurring most commonly in dark-skinned men. It is also known as acne keloidalis nuchae, acne keloid, and folliculitis keloidalis. However, these are misnomers because there is no family history of keloids, no presence of keloids at other sites, and no development of keloid formation following excision. Despite the name, acne vulgaris is not associated.

Etiology

• Unknown. Close shaving of the hair, picking by patients, and chronic rubbing by collars have been suggested as possible contributing factors. This appears to represent a foreign body granulomatous reaction to hair, with subsequent scarring.

Clinical Manifestation(s)

• Onset is usually after puberty and before age 50.

• Clinical presentation consists of a follicular pustular eruption on the nape of the neck ( Fig. 3.3 ).

  

Physical Examination

• Hard papules with hair emerging from the center are seen on the nape of neck and occipital scalp. Comedomes are not seen.

• Papules coalesce into sclerotic plaques.

• Pustules, crusting, and drainage may occur with secondary infections.

Diagnostic Tests

• Pustule swab for bacterial culture

• Deep biopsy

First Line

• Dissuade close cutting and allow hair to grow long in affected areas

• Limit mechanical irritation by a tight collar

• Encourage patient not to pick or squeeze lesions

• Topical antibiotics (clindamycin or erythromycin)

Second Line

• Oral doxycycline, tetracycline, or minocycline

Third Line

• Intralesional triamcinolone alone or following use of CO ₂ laser vaporization

• Oral isotretinoin

• Surgery: punch biopsy for small papular lesions; surgical debulking for larger lesions. Any excision must be carried out to the subfollicular depth. If any of the hair follicle is left, recurrence is common.

Definition

• Acne vulgaris is a chronic disorder of the pilosebaceous apparatus caused by abnormal desquamation of follicular epithelium leading to obstruction of the pilosebaceous canal, inflammation, and subsequent formation of comedones, papules, pustules, nodules, and scarring. Based on their appearance, the acne lesions can be divided into inflammatory (presence of papules, pustules, and nodules) and noninflammatory (open and closed comedones). For inflammatory acne, lesions can be classified as papulopustular, nodular, or both. The American Academy of Dermatology classification scheme for acne denotes the following three levels:

  • 1.

    Mild acne: characterized by the presence of comedones (noninflammatory lesions), few papules and pustules (generally <10), but no nodules.

  • 2.

    Moderate acne: presence of several to many papules and pustules (10–40) along with comedones (10–40). The presence of more than 40 papules and pustules along with larger, deeper, nodular, inflamed lesions (up to 5) denotes moderately severe acne.

  • 3.

    Severe acne: presence of numerous or extensive papules and pustules as well as many nodular lesions.

Etiology

• Acne is a follicular disease, with the principal abnormality being comedo formation.

• Overactivity of the sebaceous glands and blockage in the ducts result in acne vulgaris. The obstruction leads to the formation of comedones, which can become inflamed because of overgrowth of Propionibacterium acnes. The condition can be exacerbated by environmental factors (hot, humid, tropical climate), medications (e.g., iodine in cough mixtures, hair greases), and industrial exposure to halogenated hydrocarbons. Mechanical or frictional forces can aggravate existing acne (e.g., excessive washing by some patients to help rid them of their blackheads or oiliness).

Clinical Manifestation(s)

• Various stages of development and severity may be present concomitantly.

• Common distribution of acne is on the face, back, and upper chest.

Physical Examination

• Open comedones (blackheads), closed comedones (whiteheads) ( Fig. 3.4 )

  

• Inflammatory papules, pustules ( Fig. 3.5 ) , and ectatic pores

  

• Inflammatory and noninflammatory acneiform cysts ( Fig. 3.6 )

  

• Greasiness (oily skin)

• Presence of scars from prior acne lesions ( Fig. 3.7 )

  

Diagnostic Tests

• Laboratory evaluation is generally not helpful.

• Patients who are candidates for therapy with isotretinoin (Accutane) should have baseline liver enzymes, cholesterol, and triglycerides checked because this medication may result in elevation of lipids and liver enzymes.

• Negative urine or serum pregnancy test must be obtained in female patients one month prior to, upon initiation of, and monthly when taking isotretinoin.

• In female patients, if hyperandrogenism is suspected, levels of dehydroepiandrosterone sulfate (DHEAS), testosterone (total and free), and androstenedione should be measured. Generally, for women with regular menstrual cycles, serum androgen measurements are not necessary.

First Line

• Treatment generally varies with the type of lesions (comedones, papules, pustules, cystic lesions) and the severity of acne.

• Comedones (noninflammatory acne) can be treated with retinoids or retinoid analogs. Topical retinoids are comedolytic and normalize follicular keratinization. Commonly available agents are adapalene (0.1% gel or cream, applied once or twice daily), tazarotene (0.1% cream or gel applied daily), and tretinoin (0.1%, 0.5%, or 0.025% cream or gel applied once nightly). Tretinoin is inactivated by UV light and oxidized by benzoyl peroxide; therefore, it should only be applied at night and not used concomitantly with benzoyl peroxide. Tretinoin is pregnancy category C; tazarotene is pregnancy category X.

• Salicylic acid preparations (e.g., 2% wash) have keratolytic and antiinflammatory properties and are also useful in the treatment of comedones. Large open comedones (blackheads) may be expressed.

• Benzoyl peroxide gel (2.5% or 5%) may be added if the comedones become inflamed or form pustules. The most common adverse effects are dryness, erythema, and peeling.

• Topical antibiotics (erythromycin, clindamycin lotions or pads) can also be used in patients with significant inflammation. They reduce P. acnes in the pilosebaceous follicle and have some antiinflammatory effects. Combination products containing 5% benzoyl peroxide with topical antibiotics (3% erythromycin or 1% clindamycin) are highly effective in patients who have a mixture of comedonal and inflammatory acne lesions. Fixed-dose combinations of clindamycin phosphate 1.2% and tretinoin 0.025% are also available and are more effective than either product used alone; however, they are much more expensive than the individual generic components.

• Pustular acne can be treated with tretinoin and benzoyl peroxide gel applied on alternate evenings; drying agents (sulfa containing products) are also effective when used in combination with benzoyl peroxide.

• Azelaic acid, a bacteriostatic dicarboxylic acid, is used to normalize keratinization and reduce inflammation. It may be preferred in pregnancy (pregnancy category B).

Second Line

• Oral antibiotics (doxycycline 50–100 mg QD-BID or minocycline 50–100 mg QD-BID) are effective in patients with moderate to severe pustular acne. Erythromycin may also be used but has high rates of bacterial resistance. It is pregnancy category B.

• Patients with nodular cystic acne should be treated with systemic agents, including antibiotics (erythromycin, tetracycline, doxycycline, minocycline), isotretinoin, and/or oral contraceptives. Periodic intralesional triamcinolone injections are also effective for individual painful lesions. The possibility of endocrinopathy should be considered in patients responding poorly to therapy.

• Oral contraceptives reduce androgen levels and therefore sebum production. They represent a useful adjunctive therapy for some types of acne in women and adolescent girls but are not considered first-line therapy and should not be used as monotherapy for acne vulgaris. Commonly used agents are norgestimate/ethinyl estradiol and drospirenone/ethinyl estradiol.

• Spironolactone 100 to 200 mg/day can be administered to women only and has been shown to be particularly effective for adult-onset or “beard distribution” acne.

• Blue light can be used for treatment of moderate inflammatory acne vulgaris. Light in the violet/blue range can cause bacterial death by a photoreaction in which porphyrins react with oxygen to generate reactive oxygen species, which damage the cell membranes of P. acnes. Treatment usually consists of 15-minutes of exposure twice weekly for 4 weeks.

Third Line

• Isotretinoin is indicated for acne resistant to antibiotic therapy, severe acne, and scarring acne. Dosage is 0.5 to 1 mg/kg/day, and duration of therapy is generally 20 weeks for a cumulative dose 120 to 150 mg/kg. Before using this medication, patients should undergo baseline laboratory evaluation as described previously. Isotretinoin is absolutely contraindicated during pregnancy because of its teratogenicity. Patients, providers, pharmacies, and distributors of the drug must register in the iPLEDGE program prior to initiation of therapy.

Definition

• Acrochordons are benign outgrowths of the skin; they are also known as skin tags or fibroepithelial polyps.

Etiology

• Unknown. They are more prevalent in obese individuals and in women. Acrochordons may be associated with pregnancy and acanthosis nigricans.

Clinical Manifestation(s)

• This condition is asymptomatic unless irritated by clothing, jewelry, or friction. It is most common in middle-aged and elderly persons.

Physical Examination

• Skin-colored or brown fleshy outgrowths ( Fig. 3.8 ) are usually seen on the side of the neck and around the axillae and groin.

  

Diagnostic Tests

• None necessary. A shave/snip biopsy can be performed when diagnosis is unclear.

First Line

• No treatment is needed.

• Scissor excision with or without local anesthesia may be done for cosmetic reasons or when the skin tag is irritated.

Second Line

• Electrodessication

Third Line

• Liquid nitrogen cryosurgery

Definition

• Inflammatory reaction of the lips due to chronic and excessive sunlight exposure

Etiology

• Sunlight exposure

Clinical Manifestation(s)

• Painful erosions usually involving the lower lip

Physical Examination

• Skin appears atrophic, scaly, fissured

• Erosions may be present ( Fig. 3.9 )

  

Diagnostic Tests

• None usually needed

• Consider biopsy of any thickened or suspicious areas to exclude squamous cell carcinoma

First Line

• 5% 5-FU cream

• Topical imiquimod

• Painful areas can be treated with 5% lidocaine ointment

• Cool compresses applied PRN several times/day may be useful if inflammation is intense

• Avoidance of further sun exposure and use of sunscreen-containing lip pomades when sun exposure occurs

• Topical steroids may be used for severe inflammation and pruritus

• Mupirocin ointment and oral antistaphylococcal antibiotics if secondary infection is present

Second Line

• Cryosurgery for localized lesions

• Photodynamic therapy

• Dermabrasion

• Electrodessication

• Fractionated or ablative laser

Third Line

• Vermilionectomy of lower lip in resistant cases

Definition

• Actinic keratosis is a common skin lesion usually presenting as multiple, erythematous or yellow-brown, dry, scaly lesions in the middle aged or elderly. It is also known as solar keratosis.

Etiology

• Sun exposure, ionizing radiation

Clinical Manifestation(s)

• Typical lesions occur on sun-damaged skin of the face, neck, and dorsal aspect of hands ( Fig. 3.10 ) and forearms.

  

• Actinic keratosis is more common in males than females, especially in those with fair complexions who burn rather than tan following sun exposure.

Physical Examination

• Advanced lesions are characterized by a hard, spiky scale ( Fig. 3.11 ) and usually measure 1 cm in diameter or less. Early lesions manifest with redness and minimal scale. With progression, scales become thicker and yellow ( Fig. 3.12 ) and may resemble a small squamous cell carcinoma. On palpation, lesions are rough and gritty ( Fig. 3.13 ).

  
  
  

• The surrounding skin often shows additional features of sun damage, including atrophy, pigmentary changes, and telangiectasia.

• Classifications

  • 1.

    Hypertrophic AK with a cutaneous horn: Biopsy is necessary to distinguish the cutaneous horn from squamous cell carcinoma, seborrheic keratosis, verruca, trichilemmoma, and basal cell carcinoma. Hypertrophic AK has appearance of thick, scaling skin elevations.

  • 2.

    Lichenoid AK: Most commonly found on the torso and upper extremities. Must be distinguished from basal cell carcinoma due to pink and pearly characteristics.

  • 3.

    Proliferative AK: Often reappear after treatment and are characterized by a diameter larger than1 cm. The clinical differential diagnosis includes Bowen’s disease or SCC.

  • 4.

    Pigmented AK: Must be biopsied to distinguish from lentigo, maligna-type melanoma in situ, and solar lentigo.

  • 5.

    Actinic cheilitis: Characterized by red and sometimes abrasive lesions around the border of the lips.

Diagnostic Tests

• Skin biopsy can be performed for recurrent lesions or when diagnosis is unclear and to rule out squamous cell or basal cell carcinoma.

First Line

• Cryosurgery with liquid nitrogen

Second Line

• Topical 5-fluorouracil cream

• Topical imiquimod cream

• Topical diclofenac sodium gel

• Carbon dioxide laser

• Dermabrasion

• Curettage

Third Line

• Excision

• Photodynamic therapy with aminolevulinic acid and blue light

• Oral retinoids

Definition

• Alopecia areata is an autoimmune alopecia characterized by lymphocytic inflammation of the hair bulb and discrete patches of hair loss on the scalp and/or eyebrows and eyelashes.

• Alopecia areata affects up to 1% of the population and is more common between 15 and 40 years of age.

Etiology

• Alopecia areata is driven by cellular immunity with autoantibody production.

• The increased frequency of this disorder in genetically related individuals suggests that there is a genetic link to the disease.

• Histologically, alopecia areata is characterized by normal numbers of follicular units and hair follicles, an increase in the number of catagen and telogen follicles, and a lymphocytic infiltrate affecting the bulbs of the anagen follicles.

Clinical Manifestation(s)

• Alopecia areata patients typically present with an abrupt development of patches of nonscarring alopecia in different patterns: circumscribed ( Fig. 3.14 ) , bandlike ( Fig. 3.15 ) , and reticular. The degree of involvement is highly variable and can range from very mild disease to diffuse hair loss that may affect the entire scalp (alopecia totalis).

  
  

Physical Examination

• Examination of the involved scalp reveals that, except for the absence of hair, the skin appears normal. There are patches of acute hair loss, typically 2 to 5 cm in diameter, with normal-appearing skin, black dots (cadaver hairs, point noir) from hair that breaks before reaching the skin’s surface, and occasional “exclamation point hairs,” which are evidence of hair breaking off as they are pushed from the follicle. Fingernails may show fine pitting.

Diagnostic Tests

• Laboratory evaluation is generally not helpful.

• Antinuclear antibody (ANA), TSH, and B ₁₂ level should be considered in patients with a family history of the disease or other manifestations of autoimmune diseases.

• Ferritin level, TIBC/Serum iron, complete blood cell count (CBC) can be evaluated to rule out iron deficiency.

• RPR can be performed in selected patients to rule out cutaneous syphilis if history is suggestive of increased risk.

• On biopsy, lymphocytes surround the hair bulb and resemble a “swarm of bees.”

First Line

• Topical, high-potency corticosteroids, such as clobetasol 0.05% ointment BID

Second Line

• Intralesional corticosteroids (triamcinolone acetonide, 5–10 mg/mL, raising a small bleb within the affected patch)

• Topical minoxidil

• Topical sensitizing agent or irritants (dithranol, diphencyprone)

Third Line

• Systemic corticosteroids for 4 to 6 weeks

• Systemic immune modulators and immunosuppressants (e.g., cyclosporine, methotrexate)

Definition

• Amalgam tattoo is characterized by painless, gray, bluish, black, or slate-colored macules that occur on the gingival/alveolar ridge or buccal mucosa.

Etiology

• Particles of amalgam restorations may be traumatically implanted into the mucosa by the dentist during placement or removal of a restoration, by the patient from bite injury, from leakage and disintegration of a restoration (or root canal filling material), or from a restoration falling into a tooth socket after extraction.

Clinical Manifestation(s)

• This condition is asymptomatic, generally noted by dentist during routine dental examination.

Physical Examination

• Gray, bluish, black, or slate-colored macules can be seen on the gingival/alveolar ridge or buccal mucosa ( Fig. 3.16 ).

  

Diagnostic Tests

• None necessary. Biopsy only when diagnosis is uncertain and atypical neoplasm is being considered.

Definition

• Anagen effluvium is nonscarring hair loss of the scalp following a toxic insult to growing hair (in anagen phase).

Etiology

• Cancer chemotherapy (e.g., inhibitors of mitosis) is the most common cause.

Clinical Manifestation(s)

• Hair loss occurs usually within 2 weeks of cancer chemotherapy.

Physical Examination

• Hair loss may be slight but is often extensive.

• Alopecia is noninflammatory and nonscarring ( Fig. 3.17 ).

  

Diagnostic Tests

• None necessary.

Definition

• Androgenic alopecia is characterized by progressive patterned hair loss of the scalp due to androgens in genetically susceptible men and less commonly women.

Etiology

• Androgens are the main regulators of hair growth. After puberty, they promote transformation of vellus hair follicles, resulting in production of either tiny, nonpigmented hairs or large pigmented terminal hairs. However, androgens may also reverse this process, resulting in the gradual replacement of terminal hairs with vellus hairs and the onset of androgenetic alopecia. This phenomenon is the direct result of 5-alpha-reductase activity, which is found on the external root sheath and the hair bulb papilla. The enzyme converts testosterone into dihydrotestosterone, which has a great affinity for the androgen receptors in the hair follicle.

Clinical Manifestation(s)

• In males, the condition usually starts early after puberty, mainly affecting the crown, vertex, frontal, central, and temporal areas of the scalp (Hamilton’s male pattern). There is usually no involvement of the occipital and lower parietal regions.

• In females, the hair loss is patterned and characterized by progressive thinning over the frontal/parietal scalp, retention of the frontal hairline (Ludwig’s female pattern), and the presence of miniaturized hairs. The hair loss often starts around the onset of menopause.

Physical Examination

• In men, androgenetic alopecia presents as noninflammatory, nonscarring alopecia in defined patterns often resulting in a smooth, shiny scalp devoid of hair follicles ( Fig. 3.18 , Fig. 3.19 ).

  
  

• In women, androgenic alopecia is characterized by a noninflammatory, nonscarring alopecia that is characterized by diffuse thinning of the hair on the scalp ( Fig. 3.20 ).

  

Diagnostic Tests

• Ferritin and iron studies, TSH, serum testosterone and dihydrotestosterone levels, ANA

• Scalp biopsy if diagnosis is unclear

First Line

• Topical minoxidil 5%

• Finasteride 1 mg PO QD (men only). Dutasteride (off-label) has been shown to be superior to finasteride in a randomized trial but requires higher doses than that used for BPH.

Second Line

• Hair transplant from occipital scalp

• Hair weaves, wigs

Third Line

• Spironolactone 100 mg BID (women only)

Definition

• Mucocutaneous swelling caused by the release of vasoactive mediators. The hivelike swelling involves the deep layers of the dermis and the subcutaneous tissue.

• Angioedema is classified as acquired (allergic or idiopathic) or hereditary.

Etiology

• Angioedema is caused by mast cell activation and degranulation with release of vasoactive mediators (e.g., histamine, serotonin, bradykinins) resulting in postcapillary venule inflammation, vascular leakage, and edema in the deep layers of the dermis and subcutaneous tissue.

• Hereditary angioedema is an autosomal dominant disease caused by a deficiency of C1 esterase inhibitor (C1-INH). C1-INH is a protease inhibitor that is normally present in high concentrations in the plasma.

• Other causes of angioedema include: infection (e.g., herpes simplex, hepatitis B, and coxsackie A and B viruses; Streptococcus, Candida, Ascaris, and Strongyloides bacteria); insect bites and stings, stress, physical factors (e.g., cold, exercise, pressure, and vibration); connective tissue diseases (e.g., systemic lupus erythematosus (SLE); Henoch-Schönlein purpura); and idiopathic causes. Angiotensin-converting enzyme (ACE) inhibitors can increase kinin activity and lead to angioedema.

Clinical Manifestation(s)

• This condition is characterized by poorly demarcated, nonpruritic, burninglike edema, often involving the eyelids, lips ( Fig. 3.21 ) , tongue, and extremities, which resolves slowly.

  

• It can involve the upper airway, causing respiratory distress, and can involve the gastrointestinal (GI) tract, leading to cyclic abdominal pain.

Physical Examination

• Edema of the subcutaneous tissues, often resulting in temporary disfigurement, is seen.

Diagnostic Tests

• A detailed history and physical examination usually establish the diagnosis of angioedema.

• Extensive laboratory testing is of limited value.

• CBC, erythrocyte sedimentation rate (ESR), and urinalysis are sometimes helpful as part of the initial evaluation.

• Stool testing can be done to detect ova and parasites.

• Serology testing can be performed.

• C4 levels are reduced in acquired and hereditary angioedema (occurring without urticaria). If C4 levels are low, C1-INH levels and activity should be obtained.

• Skin and radioallergosorbent (RAST) testing may be done if food allergies are suspected.

• Skin biopsy is often performed in patients with chronic angioedema refractory to corticosteroid treatment.

First Line

• Acute life-threatening angioedema involving the larynx is treated with subcutaneous epinephrine, IV diphenhydramine, IV ranitidine or cimetidine, and systemic steroids.

• The mainstay therapy in angioedema is H1 antihistamines.

• H2 antihistamines can be added to H1 antihistamines.

Second Line

• Corticosteroids are rarely required for symptomatic relief of acute angioedema and are used more often in chronic angioedema. Prednisone 1 mg/kg/day is generally given for 5 days and then tapered over a period of weeks.

Third Line

• Tricyclic antidepressants (Doxepin 25–50 mg QD) can be used.

• Androgens (danazol, stanozolol, oxandrolone, methyltestosterone) are used for the treatment of hereditary angioedema that does not respond to antihistamines or corticosteroids. C1-INH replacement therapy (cinryze IV infusions given twice weekly; icatibant [firazyr] or ecallantide [kalbitor]) is available in some centers.

Definition

• Dilatations of the superficial dermal blood vessels in the scrotum

Etiology

• Increased venous pressure (i.e., venous insufficiency, hemorrhoids)

Clinical Manifestation(s)

• Onset generally after age 20

• Trauma/abrasion can result in significant bleeding

Physical Examination

• Multiple 1 to 3 mm red to purple papules consisting of blood vessels in the skin of the scrotum ( Fig. 3.22 )

  

• Diffuse redness of involved area may be present

Diagnostic Tests

• None needed

First Line

• Simple scissor excision

Second Line

• Electrodessication and curettage

Third Line

• Laser ablation

Definition

• Cherry angiomas (also known as Campbell de Morgan spots and senile angiomas) are very common tiny red papules on the trunk ( Fig. 3.23 ) and upper limbs of the middle aged and elderly.

  

Etiology

• Etiology is unknown. Histologically, a cherry angioma is a small polypoid lesion with an epidermal collarette and multiple lobules of dilated and congested capillaries in the papillary dermis.

Clinical Manifestation(s)

• Asymptomatic lesions appear most often in middle age and increase in size and number with age.

Physical Examination

• Smooth, cherry red lesions with shape variable from dome to polypoid papules ( Fig. 3.24 ).

  

Diagnostic Tests

• None necessary. Skin biopsy is done only when the diagnosis is unclear.

First Line

• Observation only

Second Line

• Electrodesiccation and curettage

Third Line

• Liquid nitrogen therapy

• Laser surgery

Definition

• Angular cheilitis refers to inflammation of one or both of the corners of the mouth.

Etiology

• Most unilateral lesions are due to trauma (mechanical irritation from dental flossing, excessive salivation, lip licking, mouth breathing, braces, tongue studs). Bilateral lesions are often due to infection (most often Candida albicans or S. aureus ) or nutritional deficiencies (iron deficiency, riboflavin deficiency).

Clinical Manifestation(s)

• Burning and discomfort are felt at the corners of the mouth.

• Symptoms are made worse by attempts of patients to moisten the area by licking it.

Physical Examination

• Erythema, fissures, scales, and crust may be present at the angles of the mouth ( Fig. 3.25 ).

  

• Area of fissure may be surrounded by papules and pustules.

Diagnostic Tests

• Culture for candidiasis and bacteria or potassium hydroxide preparation (KOH) preparation for fungal elements ( Fig. 3.26 ).

  

• Human immunodeficiency virus (HIV) testing in patients with risk factors

• CBC, BMP, iron, folate, and vitamin B ₁₂

First Line

• Elimination of risk factors (e.g., poorly fitting dentures, repeated attempts by patients to lick and moisten area)

• Topical miconazole or nystatin cream after meals and at bedtime

• Protective lip balms or ointments

Second Line

• Topical mupirocin if microbiology swabs reveal Staphylococcus colonization

Third Line

• Injection of collagen in the commissures when mechanical factors are causative

Definition

• Antiphospholipid antibody syndrome (APS) is characterized by arterial or venous thrombosis and/or pregnancy loss and the presence of antiphospholipid antibodies (aPL). aPL are antibodies directed against either phospholipids or proteins bound to anionic phospholipids. Three types of aPL have been characterized:

  • 1.

    Lupus anticoagulants

  • 2.

    Anticardiolipin antibodies

  • 3.

    Anti-β2 glycoprotein 1 antibodies

Etiology

• APS is an autoimmune disorder.

Clinical Manifestation(s)

• The syndrome is referred to as primary APS when it occurs alone and as secondary APS when in association with systemic lupus erythematosus (SLE), other rheumatic disorders, or certain infections or medications. APS can affect all organ systems and includes venous and arterial thrombosis, recurrent fetal losses, and thrombocytopenia.

Physical Examination

• Cutaneous: livedo reticularis ( Fig. 3.27 ) , cutaneous necrosis, skin ulcerations ( Fig. 3.28 ), gangrene of digits

  
  

Diagnostic Tests

• Diagnostic criteria for APS include at least one clinical criterion and at least one laboratory criterion.

Laboratory Tests

• Abnormal tests include:

  • False-positive test for syphilis (RPR/VDRL)

  • Lupus anticoagulant activity, demonstrated by prolongation of activated partial thromboplastin time (aPTT) that does not correct with 1:1 mixing study

  • Presence of anticardiolipin antibodies (ELISA for anticardiolipin is most sensitive and specific test [> 80%])

  • Presence of anti-β2 glycoprotein 1 antibody

First Line

• For positive aPL and venous thrombosis:

  • Initial anticoagulation with heparin, then lifelong warfarin treatment (international normalized ratio [INR] 2.0–3.0)

• For positive aPL with arterial thrombosis:

  • Cerebral arterial thrombosis: acetylsalicylic acid (ASA) 325 mg daily or warfarin therapy (INR 1.4–2.8)

  • Noncerebral arterial thrombosis: warfarin therapy (INR 2.0–3.0)

• For pregnant women with previously diagnosed APS:

  • Warfarin should be discontinued secondary to its teratogenic effects.

  • ASA, 81 mg, and heparin subcutaneously (SC) should be administered to partial prothromboplastin time PTT of 1.5 to 2 times control value.

  • Intravenous immunoglobulin (IVIG) and prednisone have also been used with success if aspirin and heparin fail.

• For pregnant women with (+) aPL antibodies and a history of fewer than three spontaneous abortions:

  • ASA 81 mg should be taken daily at conception and subcutaneous heparin 5000 to 10,000 IU q12h at time of documented viable intrauterine pregnancy (approximately 7 weeks gestation) until 6 weeks postpartum.

  • A midinterval PTT should be checked and should be normal or similar to baseline before therapy.

• For pregnant women with (+) aPL antibodies without a history of deep vein thrombosis (DVT) or pregnancy loss:

  • Consider low-dose subcutaneous heparin, ASA 81 mg, or surveillance.

• For catastrophic APS:

  • The highest survival rate is achieved with the combination of anticoagulation, corticosteroids, and IVIG or plasma exchange.

  • Case reports describe Rituximab and the monoclonal antibody eculizumab are effective for patients with life-threatening thrombosis refractory to anticoagulation.

Definition

• Stomatitis is inflammation involving the oral mucous membranes. Aphthous stomatitis is a chronic, painful, relapsing ulcerative condition of the nonkeratinized mucosa ( Fig. 3.29 )

  

Etiology

• Unknown

Clinical Manifestation(s)

• There are three variants: minor, major, and herpetiform.

• Ulcers of the minor form (the most common variant) are smaller than 1 cm, last 7 to 14 days, and heal without scarring.

• Ulcers of the major form are more common in children and adolescents, usually larger than 1 cm, last many weeks, and heal with scarring ( Fig. 3.30 ).

  

• Ulcers of the herpetiform variety occur in small crops of 10 to 100 ulcers in any one episode.

Physical Examination

• Painful, grayish white, oval ulcerations with red margins are seen inside the mouth.

Diagnostic Tests

• CBC

• Vitamin B ₁ , B ₂ , B ₆ , and B ₁₂ level; red blood cell (RBC) folate level

• Herpes simplex virus polymerase chain reaction (PCR)

First Line

• Topical corticosteroids

• Antimicrobial mouth rinses

• Intralesional corticosteroids

• Viscous lidocaine or other topical anesthetic

Second Line

• Oral corticosteroids (prednisone taper)

• Colchicine

• Sucralfate suspension

Third Line

• Pentoxifylline

• Oral acyclovir

Definition

• Atopic dermatitis is a genetically determined eczematous eruption that is pruritic, symmetric, and associated with personal family history of allergic manifestations (atopy).

• Diagnosis is based on the presence of three of the following major features and three minor features.

Major Features

• Pruritus

• Personal or family history of atopy: asthma, allergic rhinitis, atopic dermatitis

• Facial and extensor involvement in infants and children

• Flexural lichenification in adults

Minor Features

• Elevated IgE

• Eczema-perifollicular accentuation

• Recurrent conjunctivitis

• Ichthyosis

• Nipple dermatitis

• Wool intolerance

• Cutaneous S. aureus infections or herpes simplex infections

• Food intolerance

• Hand dermatitis (nonallergic irritant)

• Facial pallor, facial erythema

• Cheilitis

• White dermographism

• Early age of onset (after 2 months of age)

Etiology

• Unknown. Elevated T-lymphocyte activation, defective cell immunity, and B-cell IgE overproduction may play a significant role.

Clinical Manifestation(s)

• There are no specific cutaneous signs for atopic dermatitis, and a wide spectrum of presentations is possible, ranging from minimal flexural eczema to erythroderma.

• Inflammation in the flexural areas and lichenified skin is a very common presentation in children.

Physical Examination

• The primary lesions are a result of scratching caused by severe and chronic pruritus (“the itch that rashes”). The repeated scratching modifies the skin surface, producing lichenification, dry and scaly skin, and redness.

• In children, red scaling plaques are often confined to the cheeks ( Fig. 3.31 ) and the perioral and perinasal areas.

  

• Lesions are typically found on the neck, face, upper trunk, and bends of elbows ( Fig. 3.32 ) and knees (symmetric on flexural surfaces of extremities).

  

• There is dryness, thickening of the involved areas, discoloration, blistering, and oozing.

• Papular lesions are frequently found in the antecubital and popliteal fossae.

• Constant scratching may result in areas of hypopigmentation or hyperpigmentation ( Fig. 3.33 ) (more common in dark-skinned patients).

  

• In adults, redness and scaling in the dorsal aspect of the hands or around the fingers is the most common manifestation of atopic dermatitis; oozing and crusting may be present ( Fig. 3.34 ).

  

• Secondary skin infections may be present ( S. aureus, dermatophytosis, herpes simplex).

Diagnostic Tests

• Laboratory tests are generally not helpful.

• Elevated IgE levels are found in 80% to 90% of patients with atopic dermatitis.

• Blood eosinophilia correlates with disease severity.

First Line

• Avoidance of triggering factors:

  • Sudden temperature changes, sweating, low humidity in the winter

  • Contact with irritating substance (e.g., wool, cosmetics, some soaps and detergents, tobacco)

  • Stressful situations

  • Allergens and dust

  • Excessive hand washing

• Clip nails to decrease abrasion of skin.

• Emollients can be used to prevent dryness. Severely affected skin can be optimally hydrated by occlusion in addition to application of emollients.

• Low-to medium-potency topical steroids BID to affected areas.

• Oral antihistamines (nonsedating qAM, sedating qHS).

Second Line

• Crisaborole 2% ointment (eucrisa) is a phosphodiesterase type-4 (PDE ₄ ) inhibitor effective topical treatment for mild to moderate atopic dermatitis in patients ≥2 years old. Cost is a major limiting factor. It is administered by subcutaneous injection.

• Topical immunomodulators pimecrolimus and tacrolimus are nonsteroid antiinflammatories that may be helpful in some patients.

Third Line

• Phototherapy (Narrowband UVB)

• Systemic immunomodulators and antiinflammatories (methotrexate, cyclosporine, mycophenolate mofetil)

• Systemic biologic therapy

• Dupilumab (dupixent) is a human monoclonal antibody FDA-approved for treatment of adults with moderate to severe atopic dermatitis that has not responded to topical therapies.

Definition

• Atypical moles are also commonly known as dysplastic nevi, atypical melanocytic nevi, Clark’s nevi, and dysplastic moles.

• The term refers to nevi that demonstrate atypical color, shape, and size.

Etiology

• They can occur sporadically in 5% to 10% of the general population or as a familial syndrome (autosomal dominant trait with incomplete penetrance).

Clinical Manifestation(s)

• Atypical moles may be present on the scalp but are most commonly found on the trunk ( Fig. 3.35 ) and upper extremities.

  

• They may continue appearing into adulthood.

Physical Examination

• Diameter greater than 6 mm

• Irregular edge ( Fig. 3.36 ) that can fade into the surrounding skin

  

• Asymmetrical shape with variations in pigmentation ( Fig. 3.37 )

  

• Irregular surface, raised areas

Diagnostic Tests

• Diagnostic biopsy if suspecting melanoma

• Ophthalmologic examination (increased risk of intraocular melanoma) and examination of other family members when suspecting familial syndrome

Definition

• Bacillary angiomatosis is a vasoproliferative lesion that may be readily confused with pyogenic granuloma or Kaposi’s sarcoma and is seen predominantly (but not exclusively) in the skin.

Etiology

• The condition may be caused either by Bartonella henselae (the organism responsible for cat scratch disease) or, less commonly, by Bartonella Quintana (the cause of trench fever).

Clinical Manifestation(s)

• Patients may have systemic manifestations, including fever and malaise.

• Lesions have also been described in the bones, soft tissues, liver, lymph nodes, and spleen.

Physical Examination

• Patients present with widespread, numerous, blood-red, smooth, superficial papules and skin-colored or dusky subcutaneous nodules ( Fig. 3.38 )

  

• Hepatosplenomegaly and lymphadenopathy are also seen.

Diagnostic Tests

• Biopsy and Warthin-Starry stain/electron microscopy, PCR of biopsy material, serology, indirect fluorescence assay (IFA), prolonged culture of blood and biopsy tissue

• Complete blood cell count (CBC), HIV, alanine aminotransferase (ALT), CD4 lymphocyte count

First Line

• Clarithromycin, azithromycin, or ciprofloxacin

Second Line

• Erythromycin, doxycycline, rifampin

Third Line

• Gentamycin

• Third- and fourth-generation cephalosporins

Definition

• Basal cell carcinoma (BCC) is a malignant tumor of the skin arising from basal cells of the lower epidermis and adnexal structures. It may be classified as one of six types (nodular, superficial, pigmented, cystic, sclerosing or morpheaform, and nevoid). The most common type is nodular (21%); the least common is morpheaform (1%); a mixed pattern is present in approximately 40% of cases. Basal cell carcinoma advances by direct expansion and destroys normal tissue.

Etiology

• Risk factors include fair skin, increased sun exposure, use of tanning salons with ultraviolet A or B radiation, history of irradiation (e.g., Hodgkin’s disease), personal or family history of skin cancer, and impaired immune system.

Clinical Manifestation(s)

• Most common malignant cutaneous neoplasm:

  • 85% appear on the head and neck region

  • Most common site is the nose (30%)

  • Increased incidence with age

  • Increased incidence in men

Physical Examination

• Examination varies with the histologic type:

  • Nodular ( Fig. 3.39 ) : Dome-shaped, painless lesion may become multilobular and frequently ulcerate (rodent ulcer) ( Fig. 3.40 ). Prominent telangiectatic vessels are noted on the surface. The border is translucent, elevated, and pearly white. Some nodular basal cell carcinomas may contain pigmentation ( Fig. 3.41 ) , giving an appearance similar to a melanoma, or they may be eroded on the surface and even resemble a pyogenic granuloma ( Fig. 3.42 ).

    
    
    
    

  • Superficial: Circumscribed scaling, often black appearance with a thin, raised, pearly white border ( Fig. 3.43 ). Crust and erosions may be present. These are found most commonly on the trunk and extremities.

    

  • Morpheaform: Flat or slightly raised and yellowish or white (similar to localized scleroderma), these appear similar to scars. The surface has a waxy consistency.

Diagnostic Tests

• Biopsy to confirm diagnosis

First Line

• Treatment is variable with tumor size, location, and cell type:

  • Excision surgery: preferred method for large tumors with well-defined borders on the legs, cheeks, forehead, and trunk.

  • Mohs micrographic surgery: preferred for lesions in high-risk areas (e.g., ears, nose, eyelid), very large primary tumors, recurrent basal cell carcinomas, and tumors with poorly defined clinical margins.

  • Electrodesiccation and curettage: useful for small (<6 mm) nodular basal cell carcinomas.

  • Cryosurgery with liquid nitrogen: useful in basal cell carcinomas of the superficial and nodular types with clearly definable margins; no clear advantages over the other forms of therapy; generally reserved for uncomplicated tumors.

Second Line

• Radiation therapy: generally used for basal cell carcinomas in areas requiring preservation of normal surround tissues for cosmetic reasons (e.g., around lips); also useful in patients who cannot tolerate surgical procedures or for large lesions and surgical failures.

Third Line

• Imiquimod 5% cream can be used for treatment of small, superficial BCCs of the trunk and extremities. Efficacy rate is approximately 80%. Its main advantage is lack of scarring, which must be weighed against higher cure rates with surgical intervention.

• Vismodegib and sonidegib are orally active hedgehog pathway inhibitors recently FDA approved for metastatic BCC, recurrent basal cell carcinoma postsurgery, and locally advanced BCC in patients who are not candidates for surgery or radiation. Both medications are expensive and have medical formulary limitations.

Definition

• Becker’s nevus is an androgen–dependent lesion that becomes more prominent after puberty.

Clinical Manifestation(s)

• It usually presents in the second decade, initially as an asymptomatic light to dark brown enlarging macular lesion, which subsequently shows hypertrichosis.

• It most frequently involves the chest, shoulder, or upper arm.

• Usually, it is unilateral.

• Associated abnormalities may include unilateral breast hypoplasia, localized lipoatrophy, vertebral defects, shoulder girdle and pectoralis hypoplasia, accessory mammary tissue, and multiple leiomyomas.

Physical Examination

• Unilateral irregularly pigmented macular lesions are seen with associated hypertrichosis ( Fig. 3.45 ).

  

Diagnostic Tests

• Skin biopsy may be performed if diagnosis is uncertain.

First Line

• Clinical observation only. No treatment is necessary.

Second Line

• Q-switched ruby laser

• Normal mode ruby laser

Third Line

• Electrolysis

Definition

• Behçet’s syndrome is a chronic, relapsing, inflammatory disorder characterized by the presence of recurrent oral aphthous ulcers, genital ulcers, uveitis, and skin lesions. According to the International Study Group for Behçet’s Disease, the diagnosis of Behçet’s syndrome is established when recurrent oral ulceration is present along with at least two of the following in the absence of other systemic diseases:

  • Recurrent genital ulceration

  • Eye lesions

  • Skin lesions

  • Positive pathergy test (enlarging papules at sterile needle injection sites)

Etiology

• The etiology of Behçet’s syndrome is unknown. An immune-related vasculitis is thought to lead to many of the manifestations of Behçet’s syndrome. What triggers the immune response and activation is not yet known.

Clinical Manifestation(s)

• Behçet’s syndrome typically affects individuals in the third to fourth decade of life and primarily presents with painful aphthous oral ulcers. The ulcers occur in crops measuring 2 to 10 mm in size and are found on the mucous membrane of the cheek, gingiva, tongue, pharynx, and soft palate.

• Genital ulcers are similar to the oral ulcers.

• Decreased vision secondary to uveitis, keratitis, or vitreous hemorrhage, or occlusion of the retinal artery or vein may occur.

• Skin findings include nodular lesions, which are histologically equally divided to erythema nodosum-like lesions ( Fig. 3.46 ) , superficial thrombophlebitis, and acneiform lesions; acneiform lesions are also presented at sites uncommon for ordinary acneiform (arms and legs).

  

• Arthritis and arthralgias are common.

• Central nervous system (CNS): meningeal findings, including headache, fever, and stiff neck, can occur. Cerebellar ataxia and pseudobulbar palsy occur with involvement of the brainstem.

• Vasculitis leading to both arterial and venous inflammation or occlusion can result in signs and symptoms of a myocardial infarction, intermittent claudication, deep vein thrombosis, hemoptysis, and aneurysm formation.

Physical Examination

• Papulopustular lesions are the most commonly encountered skin manifestations.

• Recurrent oral ulceration ( Fig. 3.47 ) is an invariable feature of this condition.

  

• The ulcers measure up to 1 cm across and develop anywhere in the oral cavity, pharynx, and even the larynx. They are painful and usually regress spontaneously within 14 days. A yellow, necrotic crust typically covers the ulcer floor.

• Typical of Behcet’s syndrome and an important diagnostic clue is the development of sterile pustules at sites of mild skin trauma such as injection sites (pathergy).

• Genital lesions, similar in appearance to those of the oral mucosa, occur on the scrotum ( Fig. 3.48 ) , penis, vagina, and vulva ( Fig. 3.49 ).

  
  

Diagnostic Tests

• The diagnosis of Behçet’s syndrome is a clinical diagnosis. Laboratory tests and x-ray imaging may be helpful in evaluating the complications of Behçet’s syndrome or excluding other diseases in the differential.

• There are no diagnostic laboratory tests for Behçet’s syndrome.

• Computed tomography (CT) scan, magnetic resonance imaging (MRI), and angiography are useful for detecting CNS and vascular lesions.

Definition

• Blastomycosis is a systemic pyogranulomatous disease caused by a dimorphic fungus, Blastomyces dermatitidis ( Fig. 3.50 ).

  

Etiology

• Blastomyces dermatitidis exists in warm, moist soil that is rich in organic material. Most patients reside in the southeastern and south central states, especially those bordering the Mississippi and Ohio River valleys, the Midwestern states, and Canadian provinces bordering the Great Lakes. When these microfoci are disturbed, the aerosolized spores or conidia are inhaled into the lungs. Disease at other sites is a result of dissemination from the initial pulmonary infection; the latter may be acute or chronic.

Clinical Manifestation(s)

• Widely disseminated disease is most common in immunocompromised hosts, especially those with AIDS.

• Initial infections result from inhalation of conidia into the lungs, although primary cutaneous blastomycosis has been reported after dog bites.

• Acute infection: Fewer than 50% of patients are symptomatic. The median incubation period is 30 to 45 days. Symptoms are nonspecific and mimic influenza or bacterial infection with abrupt onset of myalgias, arthralgias, chills, and fever; transient pleuritic pain; and cough that is initially nonproductive. Resolution within 4 weeks is usual.

Physical Examination

• Cutaneous is most common and may occur with or without pulmonary disease. Two different lesions may develop:

  • 1.

    Verrucous ( Fig. 3.51 ) : This begins as a small papulopustular lesion on exposed body areas and may develop into an eschar with peripheral microabscesses.

    

  • 2.

    Ulcerative ( Fig. 3.52 ) : Subcutaneous nodules (cold abscesses) and, rarely, cutaneous inoculation blastomycosis may occur.

    

Diagnostic Tests

• Presumptive diagnosis can be made by visualizing the distinctive yeast forms in clinical specimens.

• Culture is done on Sabouraud’s or more enriched media.

• Aspirated material from abscesses

• Skin scrapings

• Prostatic secretions (urine culture with prostatic massage)

• Direct examination of specimens can be performed.

• Wet preparation with 10% KOH

• Histopathology: typically demonstrates pyogranulomas; yeast identification requires special stains

First Line

• Itraconazole is the drug of choice except for patients with CNS disease or with fulminant illness who require amphotericin B.

• Amphotericin is recommended in immunocompromised patients, those with life-threatening disease or CNS disease, or those who have failed azole treatment. This is the only drug approved for treating blastomycosis in pregnant women.

Second Line

• Fluconazole can be given if the patient is unable to tolerate itraconazole or amphotericin.

Third Line

• Ketoconazole for 6 months is an option in mild-to-moderate disease.

• Surgery may be indicated for drainage of large abscesses.

Definition

• Blue nevi represent a heterogeneous group of well-defined blue papules or nodules.

Etiology

• Arrested embryonal migration of melanocytes bound for the dermal–epidermal junction

Clinical Manifestation(s)

• The nevus appears blue gray clinically due to the deep dermal location of the melanin pigment and the Tyndall effect (the brown segment absorbs the longer wavelengths of light and scatters blue light).

Physical Examination

• Round or oval, bluish black or dark blue, sharply circumscribed, slightly elevated dome-shaped papule, nodule, or plaque ( Fig. 3.53 )

  

• Usually less than 0.5 cm diameter

• Most common on the extremities and dorsum of hands

Diagnostic Tests

• None necessary

First Line

• Benign-appearing blue nevi do not require excision.

Second Line

• Excision in rare cases of malignant transformation

Definition

• Bowen’s disease is a type of in situ carcinoma also known as intraepithelial carcinoma, Bowen’s carcinoma, or squamous carcinoma in situ, or as erythroplasia of Queyrat when involving the glans penis under the foreskin of an uncircumcised penis.

Etiology

• UV light

• Human papillomavirus (HPV)

• Chemicals (arsenic)

Clinical Manifestation(s)

• Insidious onset with slowly enlarging asymptomatic lesion

• May arise in sun-exposed (head and neck) and sun-protected areas

Physical Examination

• Scaly patch ( Fig. 3.54 ) is sharply demarcated and erythematous in appearance.

  

• Lesions may be up to several centimeters.

• Lesions are usually solitary but may be multiple in 20% of cases.

• When involving the penis, there is a red well-demarcated patch often said to be velvety but that may be quite shiny and moist appearing. Maceration may cause a white appearance and may be mistaken for candidiasis until evaporation brings out the true color.

Diagnostic Tests

• Skin biopsy

• Immunoperoxidase studies for HPV (selected cases)

First Line

• Surgical excision (for well-defined and small lesions) or Mohs micrographic surgery (for ill-defined, large lesions)

Second Line

• 5-fluorouracil cream or topical imiquimod (useful in patients with multiple lesions)

• Electrodessication and curettage

• Liquid nitrogen cryosurgery

• Photodynamic therapy (PDT)

Third Line

• Laser ablation

• Radiation therapy

Definition

• Bullous pemphigoid refers to an autoimmune, subepidermal blistering disease that is most commonly seen in the elderly. It is the most common of the autoimmune bullous dermatoses.

Etiology

• Bullous pemphigoid is an autoimmune disease with IgG and/or C3 complement component reacting with antigens located in the basement membrane zone.

• Drug-induced pemphigoid, although rare, can occur in patients taking penicillamine, furosemide, captopril, penicillin, and sulfasalazine.

Clinical Manifestation(s)

• Bullous pemphigoid typically starts as an eczematous or urticarial lesion, with the lower extremities being the most common location. Blisters form between one week and several months.

• Anatomic distribution involves the flexor surfaces of the arms, legs, groin, axilla, and lower abdomen ( Fig. 3.55 ). The head and neck are generally spared. The lesions are irregularly grouped but sometimes can be serpiginous. Oral lesions can be found occasionally.

  

Physical Examination

• The typical blistering bullae measure from 5 mm to 2 cm in diameter and contain clear or bloody fluid ( Fig. 3.56 ). They may arise from normal skin or from an erythematous base and heal without scarring if denuded.

  

Diagnostic Tests

• Skin biopsy staining with hematoxylin and eosin reveals subepidermal blisters.

• Direct and indirect immunofluorescence studies can be done to detect the presence of IgG and C3 immune complexes ( Fig. 3.57 ).

  

• Immunoelectron microscopy also reveals immune deposits on the basement membrane zone.

First Line

• Treatment of bullous pemphigoid is based on the degree of involvement and rate of disease’s progression.

• Topical steroids in general have been used in patients with localized bullous pemphigoid.

• Systemic corticosteroids are considered the standard treatment for more advanced bullous pemphigoid.

Second Line

• Azathioprine

• Mycophenolate mofetil

• Methotrexate

Third Line

• Cyclophosphamide

• Dapsone

• Plasmapheresis

• IVIG

Definition

• Burns are defined as thermal, radiation, chemical, or electrical injury to the skin.

Etiology

• Burns can be caused by excessive sun exposure ( Fig. 3.58 ) , flames, scalds ( Fig. 3.59 ) , and cigarettes, as well as chemical ( Fig 3.60 ) , electrical, and radiation sources.

  
  
  

Clinical Manifestation(s)

• Classification of burns is as follows:

Physical Examination

• Burns are defined by size and depth.

• First-degree burns (superficial) involve the epidermis only and appear painful and red.

• Second-degree burns involve the dermis and appear blistered, moist, and red with two-point discrimination intact (superficial partial thickness) or red and blanched white with only sensation of pressure intact (deep partial thickness).

• Third-degree burns (full thickness) extend through the dermis with associated destruction of hair follicles and sweat glands. The skin is charred, pale, painless, and leathery. These burns are caused by flames, immersion scalds, chemicals, and high-voltage injuries.

• The extent of a burn is described as a percentage of the total body surface area.

• Scars ( Fig. 3.61 ) may develop depending on the depth of the burn. Radiation burns may develop persistent ulcers that are difficult to heal ( Fig. 3.62 ).

  
  

Diagnostic Tests

• Chest radiographs and bronchoscopy if smoke inhalation suspected

• CBC, electrolytes, blood urea nitrogen (BUN), creatinine, albumin, and glucose

• Serial arterial blood gas (ABG) and carboxyhemoglobin if smoke inhalation suspected

• Urinalysis, urine myoglobin, and creatine phosphokinase (CPK) levels if concern for rhabdomyolysis

Definition

• Café au lait macules are well-circumscribed brownish macules caused by an increased number of functionally hyperactive melanocytes.

Etiology

• They may be found at birth in up to 10% of the population.

Clinical Manifestation(s)

• Asymptomatic

• Generally, there no associated abnormalities, but they can be markers for neurofibromatosis I, centrofacial lentigines syndrome, and Watson syndrome.

Physical Examination

• Discrete tan macules 2 to 20 mm diameter ( Fig. 3.63 ) that may be brown in darker skin ( Fig. 3.64 )

  
  

Diagnostic Tests

• None necessary

First Line

• No treatment necessary

Second Line

• Laser ablation

Third Line

• Hydroquinone 4% cream

Definition

• Candidiasis is a cutaneous or mucous membrane infection.

Etiology

• The condition is caused by the yeast Candida albicans.

Clinical Manifestation(s)

• The intertriginous skin folds such as the inner thighs, axillae ( Fig. 3.65 ) , or other moist, occluded sites such as underneath the breasts or in diaper area in infants ( Fig. 3.66 ) are most commonly affected.

  
  

• The infection may affect the foreskin and glans penis (candidal balanitis [ Fig. 3.67 ]) and the scrotum ( Fig. 3.68 ).

  
  

Physical Examination

• The affected area has a red, glistening surface with an advancing border and cigarette paper–like scaling.

Diagnostic Tests

• Diagnosis is usually made on clinical grounds.

• Presence of pseudohyphae and yeast forms on KOH preparation or other stains confirms the diagnosis.

• Serum glucose and HIV serology can be performed in recurrent cases.

First Line

• Affected skin sites that are moist should be dried out with wet-to-dry soaks and exposed to air.

• Topical antifungal products (miconazole, clotrimazole, econazole) are generally effective.

Second Line

• Oral therapy (fluconazole, itraconazole) is reserved for resistant cases.

Definition

• Cellulitis is an infection of the subcutaneous tissues.

Etiology

• Group A beta-hemolytic streptococci (may follow a streptococcal infection of the upper respiratory tract)

• Staphylococcal cellulitis

• Haemophilus influenzae

• Vibrio vulnificus: higher incidence in patients with liver disease (75%) and in immunocompromised hosts (corticosteroid use, diabetes mellitus, leukemia, renal failure)

• Erysipelothrix rhusiopathiae: common in people handling poultry, fish, or meat

• Aeromonas hydrophila: generally occurring in contaminated open wound in fresh water

• Fungi ( Cryptococcus neoformans ): immunocompromised granulopenic patients

• Gram-negative rods ( Serratia, Enterobacter, Proteus, Pseudomonas species): immunocompromised or granulopenic patients

Clinical Manifestation(s)

• Cellulitis is generally characterized by erythema, warmth, and tenderness of the area involved ( Fig. 3.69 ).

  

Physical Examination

• Erysipelas: A superficial, spreading, warm, erythematous lesion is distinguished by its indurated and elevated margin. Lymphatic involvement and vesicle formation are common.

• Staphylococcal cellulitis: The area involved is erythematous, hot, and swollen; it can be differentiated from erysipelas by nonelevated, poorly demarcated margins. Local tenderness and regional adenopathy are common. Up to 85% of cases occur on the legs ( Fig. 3.70 ) and feet.

  

• H. influenzae cellulitis: The area involved is a blue-red/purple-red. It occurs mainly in children and generally involves the face in children and the neck or upper chest in adults.

• Vibrio vulnificus: This is characterized by larger hemorrhagic bullae, cellulitis, lymphadenitis, and myositis. It is often found in critically ill patients in septic shock.

Diagnostic Tests

• Gram stain and culture (aerobic and anaerobic)

• Skin scrapings for mycology

• Blood cultures in hospitalized patients, in patients who have cellulitis superimposed on lymphedema, in patients with buccal or periorbital cellulitis, and in patients suspected of having a saltwater or freshwater source of infection

Definition

• Chancroid is a sexually transmitted disease characterized by painful genital ulceration and inflammatory inguinal adenopathy.

Etiology

• Chancroid is caused by Haemophilus ducreyi, a gram-negative facultative anaerobic bacillus.

Clinical Manifestation(s)

• Chancroid occurs more commonly in men (male-to-female ratio of 10:1).

• There is a higher incidence in uncircumcised men and in tropical and subtropical regions.

• The incubation period is 3 to 7 days but may take up to 3 weeks.

Physical Examination

• Primary lesion is one to three extremely painful, often ragged ulcers ( Fig. 3.71 ).

  

• In men, the ulcer is most commonly located on the penis.

• In women, the initial lesion is seen in the fourchette, labia minora, urethra, cervix, or anus, followed by an inflammatory pustule or papule that ruptures, leaving a shallow, nonindurated ulceration, usually 1 to 2 cm in diameter with ragged, undermined edges.

• Unilateral, often fluctuant lymphadenopathy develops 1 week later in 50% of patients ( Fig. 3.72 ).

  

Diagnostic Tests

• Darkfield microscopy of smears or aspirate

• Rapid plasma reagin (RPR)

• Herpes simplex virus (HSV) cultures

• H. ducreyi culture (difficult to culture)

• HIV testing

First Line

• A single dose of ceftriaxone 250 mg IM can be given.

• A single dose of azithromycin 1 g PO can be given.

• HIV-infected patients may need more prolonged therapy.

• Fluctuant nodes should be aspirated through healthy adjacent skin to prevent formation of draining sinus. Incision and drainage (I&D) is not recommended because it delays healing. Use warm compresses to remove necrotic material.

Second Line

• Ciprofloxacin 500 mg PO BID for 3 days

• Erythromycin 500 mg PO QID for 7 days

Note: Ciprofloxacin is contraindicated in patients who are pregnant, lactating, or younger than 18 years old.

Third Line

• Thiamphenicol

• Spectinomycin

Definition

• Chronic inflammatory lesion found on the helix of the ear

Etiology

• Unknown. Chronic sun exposure and/or chronic mechanical pressure may be contributing factors.

Clinical Manifestation(s)

• More than 90% of cases occur in men over age 40.

• Base may become red and swollen and produce significant pain.

Physical Examination

• Dull and red-white nodular mass on the helix of the ear ( Fig. 3.73 ) ; less commonly on the antihelix ( Fig. 3.74 )

  
  

• Lesions are 2 to 6 mm in diameter and well defined.

• A central scale may be present, and removal of the scale may reveal a central erosion.

Diagnostic Tests

• Biopsy of lesion if suspecting squamous cell carcinoma

First Line

• Use of special pillow to reduce pressure on area when sleeping

• Topical nitroglycerin

Second Line

• Excision of nodule

Third Line

• CO ₂ laser

Definition

• Cicatricial pemphigoid is a rare blistering disorder (incidence 1:15,000) often presenting in females in the seventh decade.

Etiology

• This is an autoimmune disorder due to autoantibodies directed against components of the basement membrane zone.

• Oral lesions occur in 85% to 95% of patients and commonly follow mild trauma.

Clinical Manifestation(s)

• Insidious onset of painful blisters occurs in mucous membranes, usually in elderly patients.

• The oral cavity is affected in 90% of cases and the conjunctiva in 70%. Other sites of involvement include the upper airway (45%), skin (30%), and genitalia (15%).

• Desquamative gingivitis is the most common manifestation. Lesions present as painful areas of erosion, erythema, and ulceration.

• Patients with this condition present with painful, swollen, erythematous lesions of the gums, which may be associated with bleeding, blistering, erosions, and ulcerations.

Physical Examination

• Bullae, erosions, and erythema most commonly affect the gingival or buccal mucosa, but the hard and soft palate ( Fig. 3.75 ) , tongue, and lips are also often involved.

  

Diagnostic Tests

• Biopsy and direct immunofluorescence studies will demonstrate autoantibodies (usually IgG and/or IgA) directed against the basement membrane zone ( Fig. 3.76 )

  

First Line

• Topical corticosteroids (fluocinonide 0.05% gel applied QID to mucous membranes)

Second Line

• Systemic corticosteroids

Third Line

• Dapsone

• Cyclophosphamide

• Azathioprine

Definition

• Edema and whealing of exposed skin areas following exposure to cold temperatures

Etiology

• Cold urticaria may be primary (essential, not associated with underlying systemic diseases or cold-reactive proteins), secondary (associated with other disorders such as cryoglobulinemia, cryofibrinogenemia hepatitis, syphilis, mononucleosis, multiple myeloma), and familial

Clinical Manifestation(s)

• Fatal shock may occur in patients with primary cold urticarial when swimming in cold water or taking cold showers

• Urticaria may occur in the nasopharynx after a cold drink

• Cold urticarial often begins after an infection

• Familial cold urticarial produces a burning sensation rather than itching and may be accompanied by fever, chills, myalgias

Physical Examination

• Presence of hive within minutes of exposure to cold

Diagnostic Tests

• Induction of hive on skin area occurs following contact with plastic-wrapped ice cube for 5 to 15 min ( Fig. 3.77 ).

  

• Urticaria does not develop during chilling but upon rewarming.

• The wheal typically lasts about 30 min.

• Cryoglobulins, ANA, ESR, RPR, cold agglutinins, RF, monospot test in suspected secondary cold urticaria

First Line

• Protection from sudden drop in temperature

• Desensitization by repeated increased exposure to cold

Second Line

• Antihistamines (cetirizine, loratadine)

Third Line

• Doxepin, cyproheptadine

• Antibiotics (penicillin)

Definition

• Benign melanocytic proliferation composed of nevomelanocytes at the dermoepidermal junction and in the dermis

Etiology

• Unknown

Clinical Manifestation(s)

• More common in older children and adults but may also be present in younger children

Physical Examination

• Flesh-colored to brown papule ( Fig. 3.78 )

  

• Elevated, uniformly round, oval, and symmetric

• Surface may be smooth or verrucous and may contain dark coarse hairs

Diagnostic Tests

• None

• Biopsy for histologic examination

First Line

• Observation and reassurance, no treatment needed

Definition

• Condyloma acuminatum is a sexually transmitted viral disease of the vulva, vagina, cervix, and perianal area in women and on the penis, perianal area, and scrotum in men.

Etiology

• HPV infection: more than 150 types of viral DNA have been identified. Transmission of warts is by direct contact. Approximately 40 different types of HPV are transmitted through sexual contact.

• Genital warts: 90% are caused by HPV types 6 or 11. HPV types 16, 18, 31, 33, and 35 are found occasionally in visible genital warts (usually as coinfections with HPV 6 or 11) and can be associated with foci of high-grade, intraepithelial neoplasia, particularly in persons who are infected with HIV infection. In addition to warts on genital areas, HPV types 6 and 11 have been associated with conjunctival, nasal, oral, and laryngeal warts.

• Virus is shed from both macroscopic and microscopic lesions.

• Predisposing conditions include diabetes, pregnancy, local trauma, and immunosuppression (e.g., transplant patients, those with HIV infection).

Clinical Manifestation(s)

• Condyloma acuminatum is seen mostly in young adults, with a mean age of onset of 16 to 25 years.

• The average incubation time is 2 months (range: 1–8 months).

• Lesions are usually found in the genital area ( Fig. 3.79 ) or perianal area ( Fig. 3.80 ) but can be present elsewhere.

  
  

• Lesions are usually in similar positions on both sides of perineum.

• The condition is usually asymptomatic, but the lesions can cause pain, odor, or bleeding.

• Vulvar condyloma is more common than vaginal and cervical.

Physical Examination

• Initial lesions are pedunculated, soft papules about 2 to 3 mm in diameter, 10 to 20 mm long; they may occur as a single papule or in clusters. There are four morphologic types: condylomatous, keratotic, papular, and flat warts.

• Size of the lesions varies from pinhead to large cauliflowerlike masses.

• Intraanal warts occur predominantly in patients who have had receptive anal intercourse, in contrast with perianal warts, which may occur in men and women without a history of anal sex.

Diagnostic Tests

• Colposcopic examination of the lower genital tract from cervix to perianal skin with 3% to 5% acetic acid

• Biopsy of vulvar lesions that lack the classic appearance of warts and that become ulcerated or fail to respond to treatment

• Biopsy of flat white or ulcerated cervical lesions

First Line

• Cryosurgery with liquid nitrogen delivered with a probe or as a spray is effective for treating smaller genital warts.

• Twenty percent podophyllin resin in compound tincture of benzoin is applied with a cotton tip applicator by the treating physician and allowed to air dry. The treatment can be repeated weekly if necessary. Podofilox (Condylox 0.5% gel) is available for application by the patient. Local adverse effects include pain, burning, and inflammation at the site.

Second Line

• Imiquimod cream is a patient-applied immune response modifier effective in the treatment of external genital and perianal warts (complete clearing of genital warts in >70% of females and >30% of males in 4–16 weeks). Sexual contact should be avoided while the cream is on the skin. It is applied three times per week before normal sleeping hours and is left on the skin for 6 to 10 hours.

Third Line

• CO ₂ laser ablation

• Sinecatechins (Veregen), a botanical drug product, is also effective for treatment of external genital and perianal warts. Formulation is a 15% ointment applied to affected area tid for up to 16 weeks.

• Application of trichloroacetic acid or bichloracetic acid 80% to 90% is also effective for external genital warts. A small amount should be applied only to warts and allowed to dry, at which time a white “frosting” develops. This treatment can be repeated weekly if necessary.

Definition

• Contact dermatitis is an acute or chronic skin inflammation or dermatitis resulting from exposure to substances in the environment. It can be subdivided into “irritant” contact dermatitis (nonimmunologic physical and chemical alteration of the epidermis) and “allergic” contact dermatitis (delayed hypersensitivity reaction).

Etiology

• Irritant contact dermatitis: cement (construction workers), rubber, ragweed, malathion (farmers), orange and lemon peels (chefs, bartenders), hair tints, shampoos (beauticians), soaps, rubber gloves (medical, surgical personnel), depilatories ( Fig. 3.81 ) .

  

• Allergic contact dermatitis: poison ivy, poison oak, poison sumac, belt buckles ( Fig. 3.82 ) , other nickel (jewelry), oils, balsam of Peru (hand and face dermatitis), neomycin ( Fig. 3.83 ) , formaldehyde (cosmetics), acrylic in adhesive tape, rubber (shoe dermatitis) ( Fig. 3.84 ).

  
  
  

Clinical Manifestation(s)

• Mild exposure may result in dryness, erythema, and fissuring of the affected area (e.g., hand involvement in irritant dermatitis caused by exposure to soap; genital area involvement in irritant dermatitis caused by prolonged exposure to wet diapers).

• Poison ivy dermatitis can present with vesicles and blisters; linear lesions (as a result of dragging of the resins over the surface of the skin by scratching) are a classic presentation.

Physical Examination

• The pattern of lesions is asymmetric; itching, burning, and stinging may be present.

• The involved areas are erythematous, warm to touch, and swollen and may be confused with cellulitis.

Diagnostic Tests

• A diagnosis of contact dermatitis is made from the history and distribution of lesions and is confirmed by patch testing to the suspected allergen ( Fig. 3.85 ).

  

• Patch testing is useful to confirm the diagnosis of contact dermatitis; it is indicated particularly when inflammation persists despite appropriate topical therapy and avoidance of suspected causative agent. Patch testing should not be used for irritant contact dermatitis because this is a nonimmunologic-mediated inflammatory reaction.

• Dermoscopy and microscopy may be useful when suspecting scabies.

• A potassium hydroxide (KOH) preparation may be useful if suspecting tinea or Candida infection.

First Line

• Removal of the irritant substance by washing the skin with plain water or mild soap within 15 minutes of exposure is helpful in patients with poison ivy, poison oak, or poison sumac dermatitis.

• Patients with shoe allergy should change their socks at least once a day; use of aluminum chloride hexahydrate in a 20% solution QHS will also help control perspiration.

• Use hypoallergenic surgical gloves in patients with rubber and surgical glove allergy.

• Cold or cool water compresses for 20 to 30 minutes five to six times a day for the initial 72 hours are effective during the acute blistering stage.

• Colloidal oatmeal (Aveeno) baths can also provide symptomatic relief.

• Patients with mild to moderate erythema may respond to topical steroid ointments or creams.

• Oral antihistamines will control pruritus, especially at night. Calamine lotion is also useful for pruritus; however, it can lead to excessive drying.

Second Line

• Oral corticosteroids are generally reserved for severe, widespread dermatitis.

• Intramuscular steroids are used for severe reactions and in patients requiring systemic corticosteroids but unable to tolerate them by mouth.

Third Line

• Phototherapy

• Azathioprine

• Cyclosporine

Definition

• A corn is a circumscribed horny, conical thickening (also known as clavus) that forms over or under weight-bearing surfaces.

Etiology

• Mechanically induced lesions due to repetitive pressure or friction

Clinical Manifestation(s)

• Pain when pressure is applied to central core

Physical Examination

• Plantar corns have a hard, painful, well-demarcated central core ( Fig. 3.86 ).

  

Diagnostic Tests

• None

First Line

• Corrective footwear to reduce pressure or friction

• Application of a ring of soft felt wadding around the region of the corn

• Soaking the feet in hot water and paring of surface with scalpel blade or pumice stone followed by application of 40% salicylic acid plaster

Second Line

• Surgical correction of the osseous deformity creating the mechanical pressure point

Definition

• Cryoglobulins are immunoglobulins that precipitate at low temperatures (4° C) and that resolve with rewarming.

Etiology

• Cryoglobulins may be divided into three classes:

  • 1.

    Type I—composed solely of monoclonal immunoglobulin (either kappa or lambda) and usually associated with lymphoproliferative disorders (multiple myeloma, Waldenstrom’s macroglobulinemia)

  • 2.

    Type II (mixed) cryoglobulin—composed of monoclonal (usually IgM) immunoglobulin

  • 3.

    Type III (polyclonal) cryoglobulin—composed of immunoglobulins IgG and IgM

• The last two subtypes (mixed cryoglobulins) function as immune complexes and clinical manifestations are due, at least in part, to allergic vasculitis.

Clinical Manifestation(s)

• The eponym Meltzer’s triad has been applied to the combined features of purpura, arthralgias, and weakness, which are often present.

• Cutaneous manifestations are common to all classes of cryoglobulinemia and are often the presenting complaint.

• Type I cryoglobulinemia is usually characterized by purpuric lesions, including inflammatory macules and papules on the extremities, accompanied by foci of ulceration.

• Mixed cryoglobulinemia is characterized by joint involvement (arthralgia and arthritis), Raynaud’s phenomenon, fever, purpura, weakness, renal involvement, hepatosplenomegaly, necrosis of extremities, and general vasculitis. Cutaneous manifestations include palpable purpura, inflammatory macules and papules, necrotizing vasculitis, and, occasionally, cold urticaria. Renal involvement may be identified by proteinuria, hematuria, and red cell casts. Patients may also have polyneuropathies.

Physical Examination

• Purpura ( Fig. 3.87 ) is the most common initial sign.

  

• Additional features may include livedo reticularis, Raynaud’s phenomenon, scarring, ulceration, and infarction, which particularly affects the digits, ears, and nose.

Diagnostic Tests

• Serum cryoglobulin level

• Skin biopsy

First Line

• Elimination of triggers by minimizing cold exposure

• Systemic corticosteroids

• NSAIDs

Second Line

• Rituximab

• Azathioprine

• Mycophenolate mofetil

• Dapsone

Third Line

• Methotrexate

• Cyclophosphamide

Definition

• CTCL encompasses a large group of lymphomatous neoplasms of T helper cells. They are initially present in the skin but may later involve lymph nodes and peripheral blood cells. Its most common form is mycosis fungoides, which is covered separately in more detail in this book. Most dermatologists use the WHO-EORTC classification for cutaneous lymphoma.

Clinical Manifestation

• Biopsy and histologic examination. Once an atypical lymphoid is identified, the initial immunoperoxidase studies usually include CD3 (T cell) or CD8 (B cell) or other markers to establish the cell line. Once identified as being of T cell origin, the next step in evaluation is to do a panel of immunoperoxidase studies (e.g., CD4, CD5, CD8, CD30).

• Important types of T-cell lymphoma that may present in the skin include:

  • Sezary syndrome (SS) is characterized clinically by pruritic erythroderma ( Fig. 3.88 ) , generalized lymphadenopathy, and the presence of circulating malignant T lymphocytes with cerebriform morphology. Diagnostic criteria include the presence of the same monoclonal population of T lymphocytes within the peripheral blood and the skin; of at least 1000 circulating Sézary cells/mm ³ and an expanded CD4+ population in the peripheral blood resulting in a markedly increased CD4:CD8 ratio; of an increased population of CD4+/CD7 cells or CD4+/CD26 in the peripheral blood; and of the loss of T-cell antigens such as CD2, CD3, and CD5.

    

  • Primary cutaneous anaplastic large cell lymphoma is type CD30+ cutaneous T-cell lymphoma that typically presents as a single or several skin lesions that have a tendency to ulcerate (50%), spontaneously regress (50%), and relapse. Lesions are usually firm, red to violaceous tumors up to 10 cm in diameter ( Fig. 3.89 ). Tumors may grow in a matter of weeks. They are rare in children and occur with slightly greater frequency in males.

    

  • Lymphomatoid papulosis is a chronic CD30+ proliferative disorder characterized by papules, necrotic papules, and/or nodular lesions that demonstrate a malignant histologic appearance; however, a benign clinical course with individual lesions may demonstrate spontaneous resolution over a period of 1 to 4 months. New crops of lesions may continue to appear for years or decades.

  • Subcutaneous panniculitis-like T-cell lymphoma most commonly presents in young adults who present with subcutaneous nodules, usually on the lower extremities. The alpha/beta phenotype is generally associated with indolent disease, and gamma/delta lymphoma, which is associated with a more aggressive course, is now considered a separate provisional entity in the WHO classification. Weight loss, fever, and fatigue are common.

  • Primary cutaneous peripheral T-cell lymphoma, not otherwise specified is a heterogeneous group of T-cell lymphomas that do not fit into the classic well-defined malignancies.

Definition

• Cutis laxa is a genetic disorder of elastic fibers resulting in decreased or absent elastic fibers in the skin.

Etiology

• Defects in at least six genes will produce congenital cutis laxa.

• Less commonly, it may be acquired and occur in association with paraneoplastic disorders, or following long-term penicillamine therapy.

Clinical Manifestation(s)

• The affected individual appears much older than chronologic age.

• Associated involvement of internal organs may result in GI diverticula, hernias, emphysema, aortic aneurysms, and ligamentous laxity.

• Severe involvement of internal organs may be fatal.

Physical Examination

• Skin is inelastic, loose, wrinkling, and sagging ( Figs. 3.90 and 3.91 ).

  
  

Diagnostic Tests

• A biopsy of skin will demonstrate a decrease in or absence of elastic fibers with special stains.

Definition

• Cylindroma is a skin lesion often found on the scalp and also known as a “turban tumor” or “tomato tumor” due to its appearance.

Etiology

• Unknown

Clinical Manifestation(s)

• Lesions may be solitary (most common) ( Fig. 3.92 ) or multiple ( Fig. 3.93 ).

  
  

• Lesions are most often found on the scalp, face, and neck.

Physical Examination

• Purplish to red nodule(s) with a smooth surface are present.

• Prominent surface vessels may be present.

• A rounded mass is seen, and skin may appear stretched.

Diagnostic Tests

• Biopsy of lesion

First Line

• Excision of lesion

Second Line

• CO ₂ laser ablation

Definition

• Cysticercosis is an infection caused by the tissue deposition of larval forms of the pork tapeworm Taenia solium.

Etiology

• Humans acquire cysticercosis through fecal-oral transmission of T. solium eggs from human tapeworm carriers, often by ingesting tapeworm eggs or cysts in contaminated food or water. The eggs hatch in the gastrointestinal tract, and larvae migrate hematogenously to tissues and then encyst, forming cysticerci. T. solium cysts, or cysticerci, may accumulate in any tissue, including the eyes, spinal cord, skin, muscle, heart, and brain. Central nervous system involvement is common and is known as neurocysticercosis.

Clinical Manifestation(s)

• Following ingestion of T. solium eggs or cysts, humans may remain asymptomatic for several years.

• The symptoms are varied and depend on the location of cysticerci. Cysticerci in muscles and skin may form “cold” nodules, which are usually asymptomatic but may calcify.

Physical Examination

• The cutaneous manifestations consist primarily of subcutaneous nodules.

Diagnostic Tests

• Definitive diagnosis is based on the histopathologic demonstration of cysticerci in the tissue involved ( Fig. 3.94 ).

  

• Peripheral eosinophilia is absent.

First Line

• Asymptomatic cysticercosis: There is no evidence that administering antiparasitic therapy is beneficial.

• Symptomatic cysticercosis: Patients with active lesions, with evidence of surrounding edema, and/or inflammation generally warrant treatment with antiparasitics (albendazole, praziquantel), corticosteroids, and anticonvulsants.

Second Line

• Surgical excision can remove solitary lesions.

Definition

• Darier’s disease is a rare skin disorder characterized by abnormal keratinocyte adhesion.

Etiology

• Darier’s disease is a dominantly inherited disorder of keratinization caused by mutations in the ATP2A2 gene.

Clinical Manifestation(s)

• Lesions may be induced or exacerbated by stress, heat, sweating, and maceration.

Physical Examination

• The nail changes in Darier’s disease include longitudinal red and/or white streaks that terminate in a notch on the free margin of the nail plate, splitting, and subungual hyperkeratosis with associated wedge-shaped onycholysis ( Fig. 3.95 ).

  

• The skin lesions are often itchy and characterized by greasy, crusted, keratotic yellow-brown papules and plaques found particularly on the scalp, forehead, ears, nasolabial folds, upper chest, back, and supraclavicular fossae.

• In some cases the lesions can be photoaccentuated ( Fig. 3.96 ).

  

Diagnostic Tests

• Skin biopsy reveals focal acantholytic dyskeratosis.

First Line

• Emollients, cool cotton clothing

• Topical retinoids (tretinoin 0.025% cream HS)

Second Line

• Oral retinoids (isotretinoin 0.3-0.5 mg/kg QD)

• Topical tazarotene gel

Third Line

• Topical 5-fluorouracil

• Cyclosporine

• Oral contraceptives

• Laser

• Dermabrasion

Definition

• Decubitus ulcers (pressure ulcers or bed sores) are defined by any damage to the skin and the underlying tissue or both that results from pressure, friction, or shearing forces.

Etiology

• Decubitus ulcers are caused by pressure, friction, or shearing forces that usually occur over bony prominences such as the sacrum or heels.

Clinical Manifestation(s)

• All pressure ulcers should be staged according to depth and type of tissue damage (see “ Physical Examination ”).

  
  
  
  

Physical Examination

Diagnostic Tests

• Tests are directed at identifying the cause of risk factors or any complications arising from the pressure ulcer (e.g., abscess or osteomyelitis); cultures of the wound bed are not helpful and should not be performed.

• Nutritional laboratory tests may reveal malnutrition.

• CBC should be obtained if infection is suspected.

• MRI or bone scans may help identify osteomyelitis when clinically suspected.

First Line

• The area should be cleaned at each dressing change; necrotic tissue should be removed.

• Debridement should be performed quickly because it delays wound healing. Whirlpool debridement may be useful.

• The wound should be irrigated.

• No one dressing or product is clearly superior; dressing should be used to keep the ulcer bed moist and protect it from urine/stool. Hydrocolloid dressings are useful for stage II ulcers. Wet dressings, xerogels, or hydrogels can be used for stage III and IV ulcers. Avoid agents that are cytotoxic to epithelial cells (e.g., iodine, iodophor, sodium hypochlorite, hydrogen peroxide, acetic acid, and alcohol).

• Reduce pressure by using a foam mattress, alternating pressure mattress, or dynamic support surface (e.g., low-air-loss bed) and by frequent repositioning (e.g., Q2H).

• Correct malnutrition.

• Minimize urinary/fecal incontinence.

• Use a standardized assessment tool (e.g., Pressure Ulcer Scale for Healing [PUSH] tool) to monitor wound healing on weekly basis.

Second Line

• Negative pressure devices (vacuum-assisted closure [VAC] devices) may help for wounds that have significant drainage.

Third Line

• Hyperbaric oxygen, ultrasound, and ultraviolet and low-energy radiation are either ineffective or have not been extensively evaluated for efficacy.

Definition

• Dermatitis herpetiformis (DH) is a chronic skin disorder characterized by an intensely burning, pruritic, vesicular rash.

Etiology

• Unknown. Increased incidence in association with HLA DRw3, B8, and DQw2, and in patients with celiac disease.

Clinical Manifestation(s)

• Pruritic, burning vesicles are seen initially; the vesicles are frequently grouped (hence the name herpetiform ).

• It may evolve in time to intensely burning urticarial papules, vesicles, and, rarely, bullae ( Fig. 3.101 ).

  

• Celiac-type permanent-tooth enamel defects are found in 53% of patients.

Physical Examination

• Symmetrically distributed vesicles and papules are seen on extensor surfaces, such as elbows, knees, scalp, nuchal area, shoulder, and buttocks, but are rarely found in the mouth.

Diagnostic Tests

• Skin biopsy of lesional skin for histologic examination characteristically demonstrates a subepidermal blister with neutrophils in the blister cavity. This pattern, although suggestive of DH, is not specific.

• A skin biopsy of uninvolved perilesional skin should be taken for direct immunofluorescence studies. Diagnosis is confirmed by granular or fibrillary IgA deposits along the subepidermal basement membrane ( Fig. 3.102 ). Biopsies should be taken from adjacent normal skin because the diagnostic Ig deposits are usually destroyed by the blistering process.

  

• Circulating antibodies include IgA antiendomysial antibody, IgA antigliadin antibodies, IgA reticulin antibody, and IgA antitissue transglutaminase.

First Line

• Adherence to a gluten-free diet has been associated with sustained remission of DH. Spontaneous remission of DH in patients on a normal diet can occur in up to 15% of cases.

• Dapsone

Second Line

• Sulfapyridine

• Systemic corticosteroids

Third Line

• Tetracycline and nicotinamide

• Cyclosporine

• Colchicine

Definition

• Dermatofibroma is an extremely common benign, slow-growing, asymptomatic dermal papule, also known as histiocytoma.

Etiology

• Unknown. The condition may occur spontaneously.

• Dermatofibroma may be associated with history of trauma (ruptured cyst, insect bite).

Clinical Manifestation(s)

• Papules are most often found on extremities (lower more commonly than upper) and scapulas.

• Papules are generally not tender but may be mildly tender on palpation.

• The condition is usually asymptomatic, but localized pruritus may be present when the lesion is initially detected.

Physical Examination

• Discrete firm dermal papules are 3 to 10 mm in diameter.

• Papules are flesh colored to violaceous to brown ( Fig. 3.103 ).

  

• The lesion dimples into the surrounding skin with lateral pinching.

Diagnostic Tests

• Biopsy of pigmented lesions to rule out melanoma

First Line

• This is a benign neoplasm that does not require treatment.

Second Line

• Surgical excision with primary closure can be performed for symptomatic lesions.

• Surgery for cosmetic reasons is best avoided because the scar from surgery may be more prominent than original lesion.

Third Line

• Intralesional corticosteroids have been used with variable results

Definition

• Dermatographism is a physical urticaria manifesting with briefly lasting linear wheals at the site of stroking of the skin ( Fig. 3.104 ).

  

Etiology

• Unknown. The condition may be associated with emotional upset, viral infections, drug reactions (antibiotics, postscabies treatment), or extreme temperature changes.

Clinical Manifestation(s)

• There is pruritus and scratching of the involved skin.

• Attacks may last from a few minutes to several hours.

Physical Examination

• Linear wheals and redness are seen at the site of stroking of the skin.

Diagnostic Tests

• Stroking of the skin with a tongue blade will elicit whealing within a few minutes.

First Line

• Elimination of potential offending agent

Second Line

• Antihistamines

Third Line

• H2 blockers