[Mastocytosis : Clinical aspects, diagnostics, therapy].

Mastocytosis is a rare, almost exclusively sporadically occurring disease involving an increase in clonal tissue mast cells. The disease spectrum is heterogenous, ranging from isolated skin lesions with a normal life expectancy to rare, aggressive forms with very poor prognosis. Children are often affected. But whereas these almost invariantly display solely a cutaneous mastocytosis with polymorphous skin lesions, in adults the lesions are small and maculopapular and in over 80% of cases accompanied by involvement of bone marrow and the D816V activating mutation of the gene for the c‑Kit receptor. There are many symptoms for the disease. Patients suffer frequently from pruritus, diarrhea, abdominal cramp, palpitations and flush. Osteoporosis is often present, with osteolysis with pathological fractures frequently involved in more aggressive forms. Patients are especially at risk to severe anaphylaxis caused by hymenoptera stings. Therapy is symptomatic, with cytoreductive therapy reserved for resistant and aggressive forms.