Mast cell activation syndrome (MCAS) is when your mast cells overreact with no known trigger. It causes severe symptoms and can lead to life-threatening anaphylaxis.

Symptoms of MCAS are caused by excessive chemical mediators released by mast cells. [10] Mediators include leukotrienes, histamines, prostaglandin, and tryptase.

Mast Cell Activation Syndrome (MCAS) happens with repeated symptoms of anaphylaxis – allergic symptoms such as hives, swelling, low blood pressure, difficulty breathing and severe …

May 27, 2024 · Mast cell activation syndrome, also called MCAS or mast cell activation disorder, is a condition that causes mast cells to release high amounts of chemicals into your body.

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The current consensus diagnostic criteria for mast cell activation syndrome (s) (MCAS [s]) were first established in 2012 and updated in 2019. This diagnosis has been attached to multiple …

Feb 27, 2025 · Did you know that Mast Cell Activation Syndrome (MCAS) often doesn’t travel alone? It’s a common comorbidity to conditions like Ehlers-Danlos Syndrome (EDS), Postural …

Nov 3, 2025 · Mast cell activation syndrome (MCAS) is a disorder in which mast cells, a normal type of cell found in your immune system, release excessive amounts of histamines and other …

Learn how to get ahead on your Mast Cell Activation Syndrome or Histamine Intolerance flare up or slow it down with a customized plan.

Dr. Jim Harris MD specializes in the diagnosis and treatment of MCAS, POTS, & EDS (Mast Cell Activation Syndrome, Postural Orthostatic Tachycardia Syndrome, & Ehlers-Danlos Syndrome)