Mast cell testing

[username]

I've been reading up on mast cell activation disorder, and it seems like it could explain a lot of my problems, why antihistamines help me with so many little things (itching, chest pains, inflammation) despite not having any allergies, and why high histamine foods give me issues. I was going to ask my PCP for whatever testing I could have done before I rush off to an immunologist/allergist, but I'm not sure which are the important ones. Figured I might as ask here since a lot of people seem to have been diagnosed, or at least gone through testing.  These are what I was looking at:

-serum tryptase

-n-methylhistamine 24hr urine

-prostaglandin d2/f2 (what is the difference between these?) 24hr urine

-leukotriene e4 24 hour urine

 

Is there anything else I should ask for? Can a PCP even order these from a regular lab? Thanks for any help.

 

 

[DizzyGirls]

My daughter had these run through her hematologist.  Her serum tryptase came out high even though she's on antihistamines!  I would certainly ask your PCP to run them.  Mine will run anything that we ask as long as it is within his parameters as a PCP. 

[Katybug]

Hi username,

This is the most comprehensive MCAS paper I've found to date. It has a list of the various things that should be considered and tested to diagnose MCAS. http://www.wjgnet.com/2218-6204/full/v3/i1/1.htm

 

[username]

I managed to get many of the tests (chromogranin A, histamine, n-methylhistamine, leukotrine e4, prostaglandin) run through my primary, but they all came back normal. One of the tests (heparin) came back with no result due to an error, and tryptase wasn't checked at all because the lab ordered something else with a similar name by accident. I asked my primary to reorder the tryptase but she said insurance wouldn't cover it if it wasn't ordered by a specialist (why she prescribed it the first time I don't know...).

Is it worth it to see an immunologist at this point to have the tryptase checked at least, or does everything else coming back normal pretty much rule out mast cell issues? I thought I was onto something with how much zyrtec helps many of my minor issues, and my reactions to high histamine/histamine liberating foods.

[DizzyGirls]

I think that no matter what the labs say, if you are being helped by something, I would stick with it (provided it doesn't clash with other medications).  I'm a firm believer in Zyrtec, too.  It makes me so sleepy, but if I skip more than a day, I have trouble breathing and I start to get vertigo.  I know that sometimes the tests will show negative, when in actually, you do have overactive mast cells.  There is always an error percent in labs.  Sure wish they would have processed the tryptase level correctly.  That was the only lab that came back high on my daughter's.  All the others were normal.  Did you go off of all of your antihistamines 48 hours before the test?

[username]

The lab ordered me a test for trypsinogen (???) instead of tryptase, which I thought would have been the easiest test to get done of the batch lol but apparently not. I had stopped taking zyrtec something like 10 days before the bloodwork, and the urine tests were done a few days after that. I was still on a low-histamine diet for the tests thou, I'm not sure if I should have been intentionally trying to provoke a flare or not.

I'm not taking any other antihistamines. I tried ranitidine as an h2 blocker for a like a week but it made me feel worse and my face broke out. In retrospect thou it might have been the red dye in it, which I know I react to. It seems impossible to find a dye-less OTC brand.