Pubic hair of infancy: endocrinopathy or enigma?

Pubic hair of infancy is a rare condition that has not been well-characterized. A retrospective chart review of infants <12 months of age who presented to our pediatric endocrine clinics with isolated pubic hair over the last 5 years was performed. Eleven patients were identified (6 male and 5 female). The average age at diagnosis was 8.3 +/- 2.0 months. The majority of patients (73%) had pubic hair in an atypical location. Growth pattern, laboratory evaluation, and bone-age radiographs were unremarkable for all the infants. Of the infants that returned for follow-up, pubic hair resolved by the age of 11.0 +/- 1.5 months. From our experience and review of the literature, we suggest that isolated pubic hair of infancy is a benign entity. However, long-term follow-up needs to be done to determine if pubic hair of infancy is an atypical variant of premature adrenarche, which may place these patients at risk for later adult disease.