Nail features in Langerhans cell histiocytosis.

We report the case of an infant who presented with isolated cutaneous manifestations of Langerhans cell histiocytosis before the evolution of systemic features. In the transition period, at 9 months of age, nail unit changes became prominent, and persisted throughout the duration of systemic treatment. A change in clinical features coincided with a course of systemic gamma-interferon, which was given because immune paresis was suspected. Nail unit changes are rare in Langerhans cell histiocytosis, and this case illustrates the range of findings, including paronychia, nail fold destruction, onycholysis with subungual expansion, and nail plate loss. The significance of these changes as a prognostic indicator is controversial.