Types Make an Appointment Refer a Patient Ask a Question Reviewed by the National Institute of Allergy and Infectious Diseases (July 01, 2009) There are two types of mastocytosis: Cutaneous mastocytosis, or skin mastocytosis. This occurs when mast cells infiltrate the skin. Systemic mastocytosis, which occurs when too many mast cells accumulate in the tissues. It can affect organs such as the liver, spleen, small intestine, and even bone marrow. Symptoms Diagnosis Clinical Trials For more than 100 years, National Jewish Health has been committed to finding new treatments and cures for diseases. Search our clinical trials.