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 the most common followed by skin lesions. Other organs involved are the lymph nodes, bone marrow, spleen, liver, lung, pituitary gland, and central nervous system. The wide variety of clinical manifestations when the onset is cutaneous, simulating other more frequent diseases, often causes a delay in diagnosis that leads to a worse prognosis of survival and subsequent sequelae. A high index of suspicion in the face of skin lesions of various kinds or of atypical presentation will lead to an early diagnosis of histiocytosis.