“…Unifocal disease in the 2-5 years age group, and multifocal multisystem disease in those less than 3 years of age. The estimated incidence of Langerhans' cell histiocytosis in the paediatric population is 3 per 10 6 children per year (Bokkerink and De Vaan, 1980). Lesions may be found in tissues of diverse origin, varying from the digestive tract, lungs and lymphoid tissues to the more commonly affected epidermis, dermis and bones (Egeler and D'Angio, 1995;Geissmann et al, 1996).…”