Nail changes in Langerhans cell histiocytosis: a possible marker of multisystem disease.

We describe a child with a 6-month history of onycholysis, subungual hyperkeratosis, and hemorrhages in most of her fingernails and toenails. Nail involvement preceded the identification of osteolytic lesions at the mastoid on a cranial computed tomography scan, which was performed because of repeated episodes of acute otitis media. Some weeks later, a small number of erythematous papules developed over the trunk and face. The diagnosis of Langerhans cell histiocytosis was made by histopathologic examination of bone, skin, and bed and matrix nail biopsies. Response to treatment with vinblastine and prednisone was excellent. Nail changes in Langerhans cell histiocytosis are extremely uncommon, particularly as the presenting manifestation of the disease. The role of nail involvement as an unfavorable prognostic sign is unclear.