Localized hypertrichosis in a pediatric patient--what is the mechanism for excess hair growth?

Localized hypertrichosis is an uncommon complaint among pediatric dermatology patients. We highlight an instance of localized hypertrichosis due to an underlying diffuse neurofibroma in a patient with known neurofibromatosis 1. The classification and possible underlying pathogenic mechanisms of localized hypertrichosis in pediatric patients is discussed.