What are Mast Cell Disorders?

To put it simply, a mast cell disorder is an immunological condition where the cells release too many histamines. The cells may do this for a combination of reasons including a weakened cell membrane, trigger foods, chemicals, exercise, or physical trauma. This causes a wide range of symptoms, with the hallmark symptoms being anaphalaxis, or symptoms that appear like an allergy attack such as hives, rashes, throat/eye/gland swelling ect..

There are different types of mast cell disorders, Mastocytosis and Mast Cell Activation Disorder/Syndrome (MCAD/MCAS) being the most common.

There is no cure for mast cell disorders, however symptoms may be managed with the use of anti-histamines, epinephrine (in situations of anaphylasis), diet/exercise/lifestyle restrictions, and sometimes mast cell stabilizers.

Diagnosis is not a simple or straightforward process. Although Mastocytosis can be detected more easily with blood tests and bone marrow biopsies, MCAD requires more precise timing. With MCAD, blood levels of Tryptase are not elevated chronically. They are only high during and immediately following anaphylasis, which means that blood must be drawn precisely at that time. If a patient hasn’t progressed to anaphylasis yet, the blood levels of Tryptase may not ever be elevated enough to be detectable with a blood test.

“So what tests can be done to determine if the mast cells are misbehaving? The first test that is usually done is a blood test for tryptase. Tryptase is a protein that comes from mast cells and it is usually elevated in two circumstances. The first is after a severe allergic reaction (anaphylaxis) and the second is if you have too many mast cells in your body (mastocytosis). If you have a significantly elevated tryptase, your doctor might recommend a bone marrow biopsy which is usually the definitive test for mastocytosis. Mastocytosis can be a serious illness, but it is different than the problem that most people with MCAS have. In mastocytosis, there are too many mast cells due to a genetic mutation that made one cell start to grow and divide without control. Patients with mastocytosis and MCAS are treated differently.”

source – Dyautonomia International – A Tale of Two Syndromes.

My doctor diagnosed me with a suspected mast cell disorder based on various factors…  my symptoms (rashes, hives, throat, gland, and eye swelling), my excessive reaction to histamine scratch test, my positive treatment results when taking anti-histamines, the fact that I do much better on a low histamine diet, process of elimination, and the fact that I have POTS since as mentioned in the link above, POTS and mast cell disorders happen together frequently. I currently take various anti-histamines throughout the day to control my reactions, and although (thankfully) I haven’t had anaphylasis yet, I carry an epi pen just in case.

For more information on mast cell disorders, see the following links!

The Mastocytosis Society

Example Low Histamine Diet pdf.

  • note that every patient is different and will have to tailor their diet to their specific needs!

Mastocytosis Society Canada – Symptom List

  • note that many symptoms overlap with those of POTS/Dysautonomia!