Category: Patient Education  

Mast Cell Activation Syndrome (MCAS)

Most Mast Cell Activation problems are due to the a variety of typical allergic problems as well as other conditions in which the mast cells are present in the body in numbers and also function as they should but are reacting to a stimulus (either internal or external).  These include allergens, autoantibodies, physical factors, infections, drugs, or certain elements of the immune system.  Secondary causes of mast cell activation are much more common than the “primary mast cell” disorders. Treating clinicians need to consider secondary mast cell activation conditions before concluding the patient has an idiopathic mast cell disease.

Labs:  Elevated tryptase levels are seen in primary mast cell diseases but also in some variants of the hypereosinophilic syndromes.  Also, about 6% of the population has an inherited condition that increases tryptase levels but does not necessarily cause symptoms.