What are mast cell disorders?

Everyone has mast cells throughout their body. When a person comes into contact with a chemical or substance to which they may react, their mast cells degranulate and give off histamine and other chemicals. The histamine and other chemicals pumped into their system by the degranulating mast cells cause the person to exhibit the symptoms we typically associate with an allergic reaction—sneezing, watery eyes, rashes, hives, itching, tongue swelling, difficulty breathing, runny nose, skin flushing, and more.

In a mast cell/mast cell activation related disorder, something has gone wrong with the mast cells. There may be too many of them, they could be irregularly shaped, or they could be degranulating—as in mast cell activation spectrum disorders—and be over-active for unknown reasons. A person with a mast cell/mast cell activation disorder may experience severe and life-threatening reactions after exposure to even very small amounts of a chemical or substance. Individuals with mast cell spectrum related disorders need to avoid exposures to the chemicals and the triggers to which they react.

Are mast cell disorders the same as chemical sensitivities or MCS?

Mastocytosis, Mast Cell Activation Syndrome (MCAS), systemic mast cell disorder are all medical diagnoses. Multiple Chemical Sensitivity (MCS) is not a medical diagnosis. Mastocytosis, MCAS, and mast cell related disorders share many of the same  symptoms. These symptoms typically include chemical sensitivity. Current research (see T.C. Theoharides, MD, here and here) has shown that the reactions to triggers individuals experience, including being sensitive to multiple chemicals, have a basis in mast cell function and mast cell degranulation.

What do I do?

If you feel that you may have a mast cell related disorder, please contact a physician to receive medical help. The information presented here is not medical advice and is in no way a substitute for receiving medical advice and treatment from a doctor.


Learn More:

About Environmental Illness (EI)

About Mast Cells

About Mast Cell Disorders



Toxins in our Lives

Pesticide Information





Education & Training

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