Signs and symptoms of Mastocytosis and Mast Cell Activation Syndrome are many and varied per patient.  Idiopathic Anaphylaxis patients experience many of the same symptoms, have few if any signs or indicators to explain their illness, but their dominant symptom of anaphylaxis persists.

The signs are caused by an over-abundance of mast cells either limited to the skin, internally or both.  The symptoms occur when mast cells are triggered to degranulate.  

Mast cell degranulation is a normal response of the immune system trying to protect the body.  However, these disorders trigger mast cell degranulation with or without an apparent or valid trigger.  Things such as foods and drinks, extreme temperatures in water or air, emotional and physical stress (to name a few) can trigger mast cell degranulation for these patients. If the patient has both an over-abundance of mast cells and excessively active mast cells (i.e. degranulating when they should not), then the symptoms and illness become more severe, prolonged and life threatening.

Some patients experience only a few symptoms, some experience many, some have all of them at various times or persistently. There is no way to fully predict what each patient will experience.

Initially, only a few signs and symptoms may be present.  Often the signs and symptoms may escalate in type, severity, frequency and persistence.  Listed below are 58 signs and symptoms reported to us by patients consistently over the past 10 years.