Diagnosis

How I got diagnosed

When I first developed symptoms of mast cell activation in the fall of 2018, I had no idea what was happening to me.

I was already seeing an allergist for my environmental allergies at an outpatient practice here in Massachusetts.

When my mast cell symptoms began, I started to experience some small reactions to food.  My doctor ran blood tests to check for allergies to about 50 different foods, and when they all came back negative, she began to suspect mast cell.

Unfortunately, mast cell disorders were something she’d only ever really heard of in passing… she had not had any training in how to treat it.  (I would later learn that there are only like 3 allergy and immunology fellowship programs in all of the US where mast cell disorders are taught).

She told me I really needed to go to one of the major Boston research hospitals.  After consulting with her supervisor, so she referred me to the allergy department at one of the Boston hospitals which was affiliated with her company.

Obviously, as this is a public blog, I am not going to say anything bad about any of the practices I went to, or the doctors who treated me.

Except I will say that the first place I went was perhaps not the best place for me to go.

My first mast cell doctor

The doctor at the first hospital I went to did have some training and familiarity with mast cell.  However, looking back, I would not say that she really had expertise.  She also had a very negative outlook on managing mast cell patients, and a lot of the things she said made me feel very hopeless about my prognosis.

However, I did need this doctor, Dr. R., to order the diagnostic tests I needed, which would allow me to later be seen by the two doctors who really did help me (Dr. Castells at Brigham and Women’s Hospital and Dr. Bayuk at Allergy and Immunology Associates of New England).

So, I am fortunate that I was able to see Dr. R. at all and get my diagnosis established.

She ordered three tests for me, which you can ask for if you would like to be evaluated for MCAS.

These tests are:

All three of these tests check for substances that are released by mast cells.  When mast cells are overactive, they release more of these chemicals, and so the patient’s levels will be higher.

It’s important to note that, even if you have a mast cell disorder, your test results may not come back positive.

Sometimes it can be a matter of timing– the goal is to catch your results while you’re actually having a flare.  If you’re not in a flare, and your mast cells are not overactive at that particular moment, your test results won’t come back high.

Unfortunately, I have heard stories of mast cell patients struggling for years to get a positive test result, even though they exhibit all of the symptoms of someone with a mast cell issues.  (My understanding is that the truly knowledgeable doctors will still treat patients based on their symptoms).

However, in my case, I was very lucky that my 24-hour urine collection for n-methylhistamine came back high.  It wasn’t crazy high– but it was still above the normal range.

Looking back, although I was devastated when my first doctor gave me these results, she was also able to give me an official diagnosis, and that did allow me to move on to other facilities where I could get better help.

A note:

The tests I listed were what Dr. R. specifically used to diagnose what she suspected was mast cell activation disorder.

However, there are additional tests that can be used to identify other types of mast cell disorders.  (For example, Dr. Castells later ordered a few tests for me that ruled out another mast cell disorder called mastocytosis).

For more on testing, check out The Mastocytosis Society‘s website.

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