Cutaneous Langerhans cell histiocytosis in children under one year

Background To evaluate the clinical course and outcome of infants with Langerhans cell histiocytosis (LCH) involving skin and to estimate the incidence of progression to multi‐system (M‐S) disease in those with isolated skin involvement. Methods A retrospective review was conducted on 22 LCH patients who were younger than 12 months at the onset of their skin eruption. Results Twelve patients had isolated skin involvement at diagnosis and 10 were evaluable for progression. Four of the 10 (40%) evaluable patients progressed to multi‐system (M‐S) disease. Of the 10 patients with M‐S disease at diagnosis, 5 had a history of a preceding skin eruption 2 to 13 months prior to diagnosis. Eleven of the 14 (79%) patients with M‐S disease had risk organ involvement. The mortality rate of M‐S disease was 50%. Conclusions It is important for primary caregivers to recognize that isolated cutaneous LCH in infants is not always a benign disorder. The diagnosis of self‐healing cutaneous LCH should only be made in retrospect. Careful, albeit non‐invasive, follow‐up is recommended to monitor for disease progression and development of long‐term complications. © 2005 Wiley‐Liss, Inc.