This past week I was diagnosed with MCAS by Dr. Castells after 1 1/2 years of symptoms and 16 anaphylactic reactions.  I've had symptom improvement on high doses of antihistamines (6 Zyrtec, 2 Allegra daily) but nothing stops the anaphylactic reactions.   Dr. Castells lowered Zyrtec to 2 daily and added aspirin and Ketotifen.  Turns out I'm reacting to Ketotifen and needed Epi.  Was very hopeful after appointment with Castells and now very discouraged because I can't take the new meds.  I see her in a month to go over test results and see if I need bone marrow biopsy.  This disease has been life changing and I do everything I can to avoid triggers but continue to struggle daily.
I have read a lot of posts here to prepare for doctor appointments and am grateful it is here to use.
AJ

angela:
first i'm sm not mcas, so a leaker not a shocker & each one of us even if diagnosis is the same are so different. my first efforts with ketotifen didn't go well. i was getting it on a script from canada for zaditan-which i name brand for ketotifen & it didn't go well, so went then tried the liquid version, again not a good result as found out the liquid version had alcohol ibn it. so went back to gastrocrom that i was on but from everything i read ketotifen was a better drug, used world wide but not in usa as not approved by the fda. i tried again 2 years ago getting it from a pharmacist in washington state who componds without all the additives that where present in the zaditan. as i stated now on 2 years & it's ended up being only drug that helped me. i had to change my zrytec to allegra as i was experience a good amount of fatigue. so i guess what i'm saying is because a drug fails one time don't rule it out forever as we are so complicated another set of circumstnaces could have cause the bad result. it's a shame but trial & error is our only method to find what works best for each of us. the advantage you have is you working with a true masto specialist, i sorry to say was not.
mikev