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.