Patient History: A 5-year-old girl presented with marked hair fragility from 7 months of age. Physical Examination: Examination revealed diffuse hypotrichosis with short, dull, fragile hair associated with areas of erythema and follicular hyperkeratosis (Image A). The vertex was the least affected area. The hair pull test was negative whereas the traction test was positive.
Trichoscopy revealed dystrophic constrictions (Image B, arrows) regularly separated by eliptical nodes that corresponded to areas of normal hair thickness, giving the hair a beaded appearance. Other findings included mild alopecia of both eyebrows, normal eyelashes, and no alterations of the nails or teeth. In the family history, the patient's mother had a similar condition that had started during childhood and affected the scalp, eyebrows, and eyelashes. At the time of consultation, the mother presented total scalp…
