The patient was an 11-year-old Hispanic girl who had an area of hair loss on her scalp that measured 6 mm in length at its maximum. Born following an uncomplicated vaginal delivery, the child was noted at birth to have a scalp ulceration that, over the course of several days, became covered with a yellow crust. By the time the child was 3 months old, the area had assumed its current appearance. It did not itch, burn, or hurt. The girl had no other medical problems. Her mother, who had had an uneventful pregnancy, had no medical problems and did not take any medications.
A 50-year-old Hispanic woman presented to the dermatology clinic with a complaint of dry skin. Incidental to this complaint was a white/ivory soft nodule in the right eyebrow. Hair follicles in this nodule were intact, and a few vellus hairs were noted growing from the skin covering the nodule. The nodule was asymptomatic. Questioning elicited history of an automobile accident three years ago that had caused traumatic abrasions over the right eyebrow to an extent exactly matched by the borders of the nodule.