Differential Diagnosis

1

Alopecia, Nonscarring

• Alopecia areata

• Anagen effluvium

• Androgenetic alopecia

• Cosmetic treatment

• Structural hair shaft disease

• Telogen effluvium

• Tinea capitis

• Trichotillomania (hair pulling)

2

Alopecia, Scarring

• Bacterial folliculitis

• Central centrifugal scarring alopecia

• Congenital (aplasia cutis)

• Discoid lupus erythematosus

• Folliculitis decalvans

• Lichen planopilaris

• Neoplasm

• Tinea capitis with inflammation (kerion)

• Trauma

3

Anhidrosis

• Central nervous system (CNS) lesions (medulla, hypothalamus, pons)

• Congenital sweat gland disorders

• Dehydration

• Drugs (anticholinergics)

• Hysteria

• Lesions of sympathetic nerves

• Local radiant heat or pressure

• Obstruction of sweat ducts (e.g., inflammation, miliaria)

• Spinal cord lesions

4

Arthritis, Fever, and Rash

• Acute rheumatic fever

• Acute sarcoidosis

• Familial Mediterranean fever

• Gonococcemia

• Hyperimmunoglobulinemia D and periodic fever syndrome

• Kawasaki syndrome

• Lyme borreliosis

• Meningococcemia

• Parvovirus B19

• Rocky Mountain spotted fever

• Rubella

• Secondary syphilis

• Still’s disease

• Urticarial vasculitis

5

Bullous Disease, Intraepidermal (Fragile Blisters)

• Bullous impetigo

• Hailey-Hailey disease

• Paraneoplastic pemphigus

• Pemphigus foliaceus

• Pemphigus vulgaris

• Staphylococcal scalded skin syndrome

6

Bullous Disease, Subepidermal (Tense Blisters)

• Acute graft-versus-host reaction

• Amyloidosis

• Arthropod bite reaction

• Bullous drug reaction

• Bullous pemphigoid

• Burns

• Dermatitis herpetiformis

• Cicatricial pemphigoid (benign mucous membrane pemphigoid)

• Epidermolysis bullosa

• Herpes gestationis

• Leukocytoclastic vasculitis

• Linear IgA disease (chronic bullous disease of childhood)

• Lupus erythematosus

• Porphyria cutanea tarda

• Pressure necrosis

• Pseudoporphyria

• Toxic epidermal necrosis

• Urticaria pigmentosa

• Variegate porphyria

7

Cutaneous Color Changes

8

Cutaneous Infections, Athletes

• Erythrasma

• Folliculitis

• Furuncles

• Herpes simplex

• Impetigo

• Molluscum contagiosum

• Otitis externa

• Tinea cruris

• Tinea pedis

• Verrucal vulgaris

9

Exanthems

• Adenovirus

• Enterovirus

• Epstein-Barr virus

• Erythema infectiosum (fifth disease)

• Kawasaki syndrome

• Measles

• Meningococcemia

• Rocky Mountain spotted fever

• Roseola exanthema

• Rubella

• Scarlet fever

• Staphylococcal scalded skin syndrome

• Varicella

10

Fever and Rash

• Allergic vasculitis

• Dermatomyositis

• Drug hypersensitivity: penicillin, sulfonamides, thiazides, anticonvulsants, allopurinol

• Erythema marginatum

• Erythema multiforme

• Erythema nodosum

• Herpes zoster

• Other infections: meningococcemia, staphylococcemia, scarlet fever, typhoid fever, Pseudomonas bacteremia, Rocky Mountain spotted fever, Lyme disease, secondary syphilis, bacterial endocarditis, babesiosis, brucellosis, listeriosis

• Pityriasis rosea

• Serum sickness

• Systemic lupus erythematosus (SLE)

• Viral infection: measles, rubella, varicella, erythema infectiosum, roseola, enterovirus infection, viral hepatitis, infectious mononucleosis, acute human immunodeficiency virus (HIV)

11

Finger Lesions, Inflammatory

• Bacterial endocarditis (Osler’s nodes)

• Dyshidrotic eczema (pompholyx)

• Herpes simplex type 1 (herpetic whitlow)

• Herpes zoster

• Paronychia

• Psoriatic arthritis

12

Flushing

• Agnogenic flushing

• Anxiety

• Carcinoid syndrome

• Chronic myelogenous leukemia (CML)

• Drugs: nicotinic acid, diltiazem, nifedipine, levodopa, bromocriptine, vancomycin, amyl nitrate

• Ingestion of alcoholic beverages

• Ingestion of hot drinks

• Ingestion of hot peppers

• Menopause

• Monosodium glutamate ingestion

• Polycythemia, systemic mastocytosis

• Renal cell carcinoma

• VIPoma (Verner-Morrison syndrome)

13

Foot Dermatitis

• Acquired plantar keratoderma

• Allergic contact dermatitis

• Dyshidrotic eczema

• Neuropathic foot ulcers (diabetes mellitus [DM], poorly fitting shoes)

• Peripheral vascular insufficiency

• Psoriasis

• Sézary syndrome

• Tinea pedis

• Tylosis (mechanically induced hyperkeratosis, fissuring, and dryness)

14

Foot Lesions, Ulcerating

• Actinomycosis (Madura foot)

• Cellulitis

• Plantar fibromatosis

• Plantar wart

• Pseudoepitheliomatous hyperplasia

• Squamous cell carcinoma

15

Genital Sores

• Chancroid

• Condyloma acuminatum

• Granuloma inguinale

• Herpes genitalis

• Lymphogranuloma venereum

• Neoplastic lesion

• Syphilis

• Trauma

16

Granulomatous Dermatitides

• Annular elastolytic giant cell granuloma (actinic granuloma)

• Cutaneous Crohn’s disease

• Foreign body granuloma

• Granuloma annulare

• Necrobiosis lipoidica diabeticorum

• Rheumatoid nodules

• Sarcoidosis

17

Hiv Infection, Cutaneous Manifestations

18

Hyperpigmentation

• ACTH–producing or MSH–producing tumors (e.g., oat cell carcinoma of the lung) ^∗

  ∗ Accentuation on sun-exposed surfaces.

• Addison’s disease ^∗

• Arsenic ingestion

• Drug induced (e.g., antimalarials, some cytotoxic agents)

• Hemochromatosis

• Malabsorption syndrome (Whipple’s disease and celiac sprue)

• Melanoma

• Melanotropic hormone injection ^∗

• Pheochromocytoma

• Porphyrias (porphyria cutanea tarda and variegate porphyria)

• Pregnancy

• Progressive systemic sclerosis and related conditions

• Psoralen and UVA (PUVA) therapy for psoriasis and vitiligo ^∗

19

Hypertrichosis