I'm with a UK based doctor right now who by all accounts is good, but we're going very slowly on the medications - he got my to try antihistamines for 2 months (loratidine and famotidine) but these didn't help, so I'm just about to start Ketitofen and then reassess after another 2 months.
All seems incredibly slow :/ is this the standard approach? I'd like to bring up with IVIG and Rituximab with him too, this thread is the first I've heard of any of these things mentioned.
That actually seems quite enlightened for a UK based doctor! The typical things the best in the US do or to put patients on both an H1 and an H2 antihistamine as well as a mast cell stabilizer or two or three.
The different H1 antihistamines seem to work differently in people, I never got any help from loratadine or cetirazine. I was helped by Allegra, but as with all FDA approved antihistamines in the US, It contains milk products so I had to have it compounded for a $400 bottle of pills. Ketotifen is actually much cheaper to compound.
So, the doctors pick between different H1 antihistamines and if one doesn't work then try another. The famotidine is one of two H2 antihistamines, the other being ranitidine, but there have been ingredient problems with ranitidine so the famotidinei s a logical choice.
Your doctorctor has not taken the next logical step of adding mast cell stabilizers, which would be quercetin, cromolyn sodium, had a bunch of others, but those are the most common. I've taken up to 2 g of quercetin a day, and at one point was on 1.6 grams of cromolyn sodium as well. Mast cell expert Theo Theoharidas developed a botanical mast cell stabilizing product called Neuroprotek which some people around here take and have good luck with. My doctor also prescribes montelukast, a leukotriene inhibitor. It also depends on which mast cell chemicals get released in your system.
There are definitely some more heavy-duty drugs, the most expensive and exotic being imatinib, which goes for $128,000 a year here in the US, but there are other approaches as well.
For acute mast cell problems, a benzodiazepine like lorazepam can be useful, In addition to more common drugs like Benadryl, oral, injectable, or IV.
I've attached 2 documents to share with your doctor, one from expert Lawrence Afrin on drugs for MCAS, and the other a case study of a woman dramatically helped by IVIG.
I'd also love to address whatever is underlying it, I know I have gut dysbiosis, SIBO, and I've recently tested positive for high mycotoxins, no doubt that one or all of these is contributing to MCAS but I simply cannot tolerate any treatment at the moment, anything like probiotics and it triggers my MCAS.
There are definitely a number of factors that increase one's mast cell reactivity. Working on reducing each one of those that you have is extremely useful.
Best wishes.