Question

Discussion

The answer is A: alopecia areata. This T cell–mediated autoimmune disease has a lifetime prevalence of about 2%.¹ It is characterized by a localized area of complete hair loss with normal skin pattern. Alopecia areata has a sudden onset and may involve the entire scalp (alopecia totalis) or the entire body (alopecia universalis).² Alopecia areata increases the risk of other autoimmune disorders.³

The diagnosis is usually made clinically; however, a skin biopsy may be performed if the diagnosis is unclear.^1,4,5 Spontaneous remission is common and usually occurs within six to 12 months.^1,2 Topical, intralesional injection and, occasionally, systemic glucocorticoids are used for treatment.^1,2,5 Immunomodulating agents (e.g., irritant dithranol, diphenylcyclopropenone) and topical minoxidil have been used with variable results.^1,4,5

Cicatricial alopecia is permanent hair loss caused by destruction of the hair follicles by inflammatory or autoimmune diseases, commonly discoid lupus erythematosus.^2,5 The condition causes folliculitis and eventually leads to scarring and skin atrophy.

Tinea barbae is an uncommon fungal infection that most often occurs in farm workers.⁶ It usually causes pruritic, erythematous, and scaling patches with fragile, broken hairs.^2,5 Pulling infected hairs is usually painless.⁶

Traction alopecia is unintentional hair loss due to high-tension grooming style.^2,5Although it can occur in the beard, it is more common on the scalp. In rare cases, chronic traction alopecia results in folliculitis and scar formation.⁵

Trichotillomania is a compulsive disorder that involves repetitive hair pulling.^2,5 The most common location is the scalp.² Scar formation occurs in rare cases.^2,5