Focal hair loss

Clinical features

Alopecia areata (AA) is a common cause of hair loss that affects men and women equally and can affect patients of all ages.

• AA is the second most common cause of nonscarring hair loss after androgenetic alopecia (AGA; also known as “male/female pattern hair loss”).

  • It is of unclear etiology but is thought to be immune mediated via loss of tolerance and has a link to other autoimmune diseases.

• This disease happens in all age groups but is more common in younger individuals.

• AA can affect any hair-bearing area, but the scalp is most commonly affected ( Fig. 14.1 ).

  • Other affected areas include the eyebrows, facial hair ( Fig. 14.2 ), and body hair.

    

  

• There are multiple different clinical subtypes. These include patchy, pattern, totalis, and universalis.

  • Patchy is the most common subtype and involves one or more (typically annular) patches, which can present on any hair-bearing area.

  • Pattern is less common but comes in many patterns, ranging from diffuse to ophiasis, sisiapho, and reticular.

  • In totalis AA, all of the hair on the scalp is affected.

  • In universalis AA, all of the hair on the body is affected.

  • There may also be nail findings of AA, typically involving pitting.

• AA involves one or more painless patchy areas of hair loss, although white hairs may be spared and when new hair growth (short hair) is visible, it may also be white.

• The area of hair loss does not appear to be red or inflamed on a physical examination.

• AA typically presents as a sudden patch of hair loss on the scalp. The process is painless and noninflammatory.

  • Patients often state, “I lost this patch of hair overnight.” The patient does not report clumps of hair coming out as is reported in telogen effluvium (TE).

• AA is an autoimmune disease, which is associated with other autoimmune diseases, including rheumatoid arthritis, vitiligo, and autoimmune thyroid disease.

  • AA is also strongly associated with atopic dermatitis (AD).

• Because AA has a strong genetic component, it is important to ask about family history.

• As with all conditions, AA may exist within the context of other hair pathologies (i.e., a patient with AGA may have coexisting AA).

• Prognosis depends on age of first presentation (younger is worse) and extent of disease (more extensive is worse).

• About 50% of patients have hair regrowth without treatment within 1 year.

Differential diagnosis

The differential for AA includes tinea capitis, AGA, trichotillomania, TE, anagen effluvium, and psychogenic pseudoeffluvium.

• Tinea capitis, especially in children, can present as one or more patches of hair loss. It is distinguished from AA because tinea capitis has inflammation and scale. If the diagnosis is unclear, a fungal culture can differentiate between the two. Tinea capitis also resolves with antifungal treatment and has classic potassium hydroxide (KOH) of hair scraping, showing a hyphae (long) and yeast (round) with spaghetti (long) and meatball (round) appearance.

• AGA can coexists in middle-aged to older patients with AA where the patient will present with a new patch of hair loss in the background setting of AGA. Other subtypes of AA, including the diffuse subtype, can present with diffuse hair thinning and can be easily mistaken for AGA. Timing is very important here. AGA is a much slower process (years) compared with AA (days or weeks) and thus completing a patient history is critical before providing additional work-up. The pattern of hair loss (location on the head) is also important because AGA favors the frontotemporal and occipital areas.

• Trichotillomania, which commonly presents in children, is caused by obsessive hair pulling/twisting and can cause patchy hair loss, which resembles AA. Patients can be observed for hair-pulling behavior and there are various physical examination findings, including hairs of various different lengths and an abundance of split ends, which should raise suspicion. Trichotillomania often coexists with other psychiatric conditions, including obsessive-compulsive disorder (OCD).

• TE patients typically present with complaints of hair shedding in clumps. This type of hair loss is diffuse; therefore it should be easily distinguished from the classic patchy AA. Distinguishing between diffuse AA and TE can be very difficult and relies on biopsy findings or results of a modified hair wash test.

• Anagen effluvium is a form of diffuse hair loss that is triggered by chemotherapeutic-based destruction of hair follicles, leading to rapid, diffuse hair loss. Patient history is critical for establishing this diagnosis.

• Psychogenic pseudoeffluvium is another psychiatric-associated hair condition, and it occurs when patients are intentionally causing hair loss for secondary gain. This is usually discovered when work-up, including biopsy, is not revealing.

Work-up

Work-up for AA is divided into history taking, clinical examination, and laboratory work-up.

Clinical examination

• History and visual examination are all that are required to diagnose the common variants of patchy AA. Document the pattern of hair loss, including whether there is a single patch or multiple patches and what the specific patterns are (diffuse, ophiasis, sisiapho, reticular).

• Evaluation with a dermatoscope or other form of magnification (such as a jeweler’s loupe, which is very inexpensive and readily available online) can be helpful. The classic findings on magnification are yellow dots (keratin in the follicles) and exclamation mark hairs (thinner proximally), although these findings are nonspecific. A positive hair pull test (during active disease) can be helpful in differentiating AA from trichotillomania and psychogenic pseudoeffluvium, but this is not typically done. Biopsy can also be done in cases of diffuse AA that are more difficult to diagnose.

• White hairs can be spared, and new hair growth may be white.

• Pictures should be taken (with a ruler) to document changes in future visits.

Laboratory work-up

Laboratory work-up is not necessary unless there is suspicion for thyroid disease, which is a common coexisting disease (both are autoimmune). In that case, thyroid-stimulating hormone (TSH), T3, and T4 should be tested.

Initial steps in management

There are no U.S. Food and Drug Administration (FDA)–approved treatments for AA, and the literature lacks high-quality randomized trials for this disease. Nevertheless, there are multiple treatment options. Patients should be counseled on this and on the fact that hair regrowth, even with treatment, will take a minimum of 3 months.

• The most common treatment modality for patchy disease on the scalp is local injection of corticosteroids. Triamcinolone acetonide is the most commonly used option and treatment involves multiple injections approximately 1 cm apart and 0.1 mL in volume. These injections are painful, require multiple treatments at 1-month intervals, and can result in skin atrophy, among other complications. It should be noted that these treatments do not prevent AA from developing in other areas. If there is no response after 6 months, local injections should be stopped.

• Topical corticosteroids can be trialed for isolated AA patches on the scalp. Options include clobetasol foam and lotion. This treatment is less likely to work than local corticosteroid injection. Moreover, clobetasol is a very potent steroid and can cause local atrophy. Patients should be counseled to only use this on areas on the scalp. Similar to injections, the treatment should only last for 6 months. Patients should take 2 days off treatment per week and should have regular follow-up visits to assess progress and check for side effects.

• Systemic corticosteroids (either pulsed-dose oral steroids or intramuscular steroids) have also been used for treatment, but the side effects can be significant and rebound after discontinuation is common. This treatment is only reasonable in cases of debilitating hair loss where patients are accepting of the inherent risks of long-term corticosteroids.

• About 50% of patients have regrowth within 1 year with no treatment. Some male patients prefer to shave their heads to cover up the areas of disease.

• Trichopigmentation is a form of nonpermanent hair tattooing that has been helpful for concealing areas in some patients, especially eyebrow loss in severe cases.

• Laser treatments (by excimer lasers) are another nonmedical option, but the evidence for these treatments is not robust.

• In terms of upcoming treatments, Janus kinase (JAK) inhibitors offer promising hope for severe and treatment-resistant diseases. Multiple biologic antibodies are also currently being tested and the next 10 years are sure to bring exciting developments for therapy.

• Hair prosthesis (i.e., medical-grade wigs) should be considered in all cases of diffuse hair loss, especially in children, where current therapies are poorly tolerated,

• Although it will not affect the AA, treat a thyroid disease if it is identified.

• Topical minoxidil has not been shown to have any benefit for patients with AA.

• All patients should monitor their hair loss at home with serial pictures.

Warning signs/common pitfalls

Do not downplay the patient’s concern regarding the alopecia, no matter how limited the disease may be. Patients should be counseled regarding the risks and benefits of treatment. Scheduling regular follow-up visits and assessing the need for psychological support, especially for severe AA cases, are also important steps. Children with this disease are often bullied extensively and special precautions warning teachers and counselors may be necessary.

Counseling

You have a type of hair loss called “alopecia areata.” It is caused by an autoimmune reaction against the hair follicles. The trigger for this is not clear, but there is a strong genetic component. There is a large spectrum of disease. Most commonly, one or a few patches of hair are lost, and this can happen anywhere on the body. The disease fortunately goes away on its own in about a year in half of all cases. The most common treatment for this disease involves steroid injections into the affected region on the scalp. There are also multiple cosmetic options we can explore. This type of hair loss can be very distressing, and we are here to help should you need any type of emotional support.