What are the signs of mastocytosis or mcas?

Hives, anaphlaxis: Cutaneous mastocytosis typically presents as small brown splotches that turn in hives or welts when irritated, but it can affect the entire skin surface, too. Systemic masto and MCAS typically presents with spontaneous episodes like anaphylaxis--dizziness, fainting, flushing, nausea, diarrhea, and sometimes hives and trouble breathing. See a specialist in masto for more info.