Pam,

Hi! I start to forget who I tell what, so I am not sure if I have relayed this info to you. MCAS generally does not test positive to anything. If the symptoms are MCAS and the tests are coming back negative, then that IS your indication that it is MCAS. The tests that are being done are to rule OUT OTHER conditions. There is no test for MCAD.  If your doctor thinks he or she is testing for MCAS, then you need a new doctor because that is a doctor who lacks knowledge of MCAS. MCAS is such a newly accepted condition that most doctors do not know about it or how to figure it out. Dr Castells coined the term MCAS and she is the only Masto specialist who sees kids. We have a forum member who just posted today that although she thought her doctor had to refer her to see Castells, she followed forum advice and called Dr Castells's office herself. The office took her self-referral! Dr Castells requested to see her doctor's file on this patient. This is what other patients report and generally it results in a phone consultation with Dr Castells. This would be perfect for you! You just have to make sure that you explain correctly what is going on when you call Dr Castell's office that first time. If you would like pointers on phrasing, please let me know, as it is important to make the correct impression when you call.

Dr. Afrin generally points out that while MCAS patients DO have elevated mast cell mediators, modern medicine can only test for a small number of them, so the patient will often test negative even though they have MCAS.  I tested negative for just about everything until I had a very broad panel done at MUSC.  

You also have to realize that most patients and labs don't handle the 24-hour urine specimen and some plasma and serum specimens properly for things like PGD2 and heparin.  Some of them have to have the container chilled before collection, and the specimen must remain chilled from time of collection all the way through transport to the processing lab.  If not, the mediator degrades very quickly and the test will come back negative.  Even though I was meticulous, my 24 hour urine PGD2 came back normal, but my plasma PGD2 was elevated.  I watched the lab technician chill the tube on ice and put it straight back on ice before and after my draw.  It is that sensitive.

What was your daughter's heparin level?  According to Dr. Afrin, anything over .02 (on his lab's reference range) is elevated.

All I'm trying to say is that you have not ruled out MCAS just because you don't have positive test results.  It just means you haven't confirmed anything yet.  Dr. Afrin was pretty much convinced I had MCAS without the tests based on my medical history, physical exam and positive response to antihistamines.  He just used them to confirm my diagnosis, and to feel more confident in recommending further medications.

I know how unbelievably frustrating it is to have tests come back normal (that's been my life for eight years until last month!), but I think you should try to push to get her in to see Dr. Castells.  My doctor's office got stonewalled by her staff, even after she told my doctor to send my records, so I gave up, but other people have had success with calling her office (maybe more than once, if you get shut out the first time).  I just don't think anyone but the experts (and their experienced lab technicians) can properly evaluate an MCAS patient.

Pam,
I agree you should be able to get a phone consultation pretty easily with Dr. Castells.  The experts know that you can have mediator negative MCAS.  I do believe it is because science isn't there yet like what was mentioned prior.

My daughter is finally starting to make some positive changes on ketotifen and doxepin.  This is the first time in one year (after treating POTS) that she is making a positive change.  My daughter's tests came back negative too but she gets better with benadryl and mast cell stabilizers so I don't think we need a positive lab test to say she has it.

You are on the right path.  Trust your gut.  Push for getting one of the experts to review your daughter's records and make a plan.  I know how hard this is...Once I got the phone consult date and now the appt with Dr. Castells I started to feel better.  It is hard to expect your daughter to improve without a plan or change in what you are doing...I know that road...

Keep coming here for advice.  There are some amazingly knowledgable people and you will feel stronger and supported.