Mast Cell Activation Syndrome

Mast cell activation syndrome (MCAS) involves the skin, gastrointestinal, cardiovascular, respiratory, and neurologic systems, classified as primary, secondary, and idiopathic. Earlier criteria for MCAS diagnosis included episodic symptoms with mast cell mediators affecting two or more organ systems with urticaria, angioedema, flushing, nausea, vomiting, diarrhea, abdominal cramping, hypotensive syncope, tachycardia, wheezing, conjunctival...