Hypertrichotic Plaque in a 17-Month-Old Boy

Abstract

A 17-month-old boy was referred to pediatric dermatology for evaluation of a slowgrowing, nontender plaque on the lower back. The child's mother reported that, on discovery, the plaque was initially 1 × 1 cm and had since grown in size with the child. She was uncertain if the plaque was present at birth. The patient's medical history was significant for dermal melanocytosis of the right hip and mid back, increased head circumference (97th percentile), and expressive language delay. There was no family history of congenital birthmarks or neurofibromatosis type 1 or 2.Physical examination revealed a well-appearing boy with normal vital signs and Fitzpatrick type III skin type. On the left lower back, there was a 15 × 5-cm indurated skincolored to yellow, firm, multinodular plaque with hypertrichosis, extending from the midline to the left lower flank (Figure , A). There were additional blue-gray patches on the back and right hip, as well as a small café au lait macule on the right lower back. Limited neurologic examination was within normal limits. A 4-mm punch biopsy was performed for further diagnostic evaluation (Figure , B-D).