Langerhans cell hyperplasia of the skin mimicking Langerhans cell histiocytosis: a report of two cases in children not associated with scabies.

Langerhans cells histiocytosis (LCH) affecting the skin most commonly has clinical and histopathologic diagnostic features. We are reporting two examples of Langerhans cell (LC) hyperplasia recognized in the skin biopsies of two children initially interpreted as LCH. The first was an 8-year-old boy finally interpreted as having an atypical type of contact dermatitis, while the second, an 8-year-old girl, was assumed to have Pytiriasis lichenoides et varioliformis acuta. None showed evidences of scabies. Both presented spongiotic dermatitis with numerous CD1a+ cells. As more cases of LC hyperplasia are recognized, new details emerge helping in the differential diagnosis. Strict clinical-pathologic correlation is suggested in order to avoid misdiagnosis.