Explanation
Exclamation point hairs
Educational objective: Alopecia areata is characterized by patchy, painless hair loss with no erythema, scaling, or scarring. It is an autoimmune disorder and is often associated with other autoimmune conditions (eg, autoimmune thyroid disease). Treatment includes topical or intralesional corticosteroids. A recurring course is common, but most patients have regrowth over time.
Choice B. Discoid lupus erythematosus of the scalp causes hair loss with inflammation, scarring, and hypopigmentation (see image) of the skin. There are often additional lesions on the face or extremities.
Choice C. Pediculosis capitis (head lice infestation) presents with pruritus of the scalp and visible nits (see image). It is not typically associated with hair loss.
Choice D. Telogen effluvium is characterized by diffuse, rather than patchy, hair loss. It is often triggered by physiologic stressors (eg, severe illness, pregnancy, endocrine disorders) or emotional distress.
Choice E. Tinea capitis is a superficial dermatophyte infection that presents as a scaly, erythematous patch of hair loss. There are often small,black dots (see image) , representing broken shafts, and (sometimes) tender lymphadenopathy.
Choice F. Trichotillomania is characterized by self-induced hair pulling. It causes patchy hair loss, but usually shows signs of regrowth (see image) with new hair shafts of various lengths. It commonly occurs on the patient's dominant side (ie, usually right).
