Mastocytosis happens when too many mast cells build up in the body. Mast cells are a type of white blood cell that play an important role in helping the immune system defend the body from disease. They also respond to allergic reactions, help heal wounds, and defend against infections. 

Cutaneous mastocytosis occurs only in the skin. The main symptom is itching. In systemic mastocytosis, however, there are too many mast cells throughout the body, including in the gastrointestinal tract and the bone marrow. When the disease is in the intestinal tract, it can lead to nausea, vomiting, diarrhea, and abdominal pain.

To diagnose this disorder, our doctors may take a biopsy (sample) of the bone marrow or gastrointestinal tract. A biopsy can show whether mast cells are in parts of the body other than the skin.

Our doctors typically treat the illness with antihistamines, drugs that are used for people with allergies. For more severe cases, we may recommend steroid or chemotherapy treatment. A targeted drug called midostaurin (Rydapt®) is approved to treat more-aggressive cases of systemic mastocytosis. Finally, our scientists are researching new drugs for people with systemic mastocytosis that carries certain mutations.