What is the difference between Mast Cell Activation Syndrome (MCAS) and histamine intolerance?

    Can I have both? One of the chemicals your mast cells release when triggered is histamine. You’re probably familiar with histamine from antihistamine medications and creams for seasonal allergies and bug bites. Looking at the “anti” part of antihistamine may give you the impression that histamine is something undesirable or not good for you. This is absolutely not the case. Histamine is essential for immune function and overall body health. Histamine allows your body to remove allergens. It also supports normal digestion by releasing hydrochloric acid to break down food. Last but not least, histamine is essential for brain, neurological, and mental health, as it functions as a neurotransmitter, or chemical messenger between your brain and the rest of your body. If there is too much histamine for your body to handle, you may have a histamine intolerance. If you are exposed to, produce too much of, or do not properly eliminate histamine, this buildup of histamine can lead to a number of chronic symptoms. This is considered histamine intolerance. Many of these symptoms can resemble or overlap with MCAS, which makes the situation more confusing.

    Histamine intolerance develops due to an overabundance of histamine from several sources, including a histamine-rich diet, stress, toxins, infections, from mast cells that release histamine, or even from other cells such as basophils that release excess histamine, combined with your body’s inability to break down this excess.

    You can now see that MCAS can lead to histamine intolerance due to an increase in histamine release, but histamine intolerance does not cause MCAS. MCAS and histamine intolerance are not the same thing, but they often occur together. Many patients with MCAS also have histamine intolerance. This is not the case for everyone, however, and some people with MCAS may never develop histamine intolerance. If you are experiencing symptoms of MCAS or histamine intolerance, it is recommended that you seek out a functional medicine physician or functional nutritionist to receive the correct diagnosis and appropriate treatment.