Langerhans cell histiocytosis. Onset with vesicular rash

Langerhans cell histiocytosis is a group of rare diseases characterized by tumor infiltration of almost any organ in the body by cells of the mononuclear phagocytic system. Bone involvement is most common, followed by skin lesions. Other involved organs may include the lymph nodes, bone marrow, spleen, liver, lung, pituitary gland and central nervous system. In cases with cutaneous onset, the broad heterogeneity of clinical manifestations, mimicking other, more frequent diseases, often causes a delay in diagnosis that leads to a poorer prognosis in terms of survival and future sequelae. A high index of suspicion in the presence of skin lesions of varying nature or with an atypical presentation will allow early diagnosis of histiocytosis.