I have only used ketotifen for eye drops and somehow had a weird outbreak on my eye lid. I assumed it was a coincidence and waited until the outbreak cleared up. Then I tried again. Same thing happened. I stay away from ketotifen. I could imagine what it would do to me more concentrated. I tried Xolair treatments for a good while. It helped for like a year and a half but then stopped. My mast cell is a little more aggressive (it may actually be mastocytosis) so this is typical. Xolair I found was incredibly helpful and for most people, it can actually help long term. Worth looking into

I do fine with Ketotifen. Maybe your Dr could start with a lower dose and titrate up? A lot of people use Gastrochrom instead. It’s a liquid. ( or both)

I also had a reaction to that one at one point. I have a very complex combination of medication but am finally to a very stable point with my mcas. -mega dose antihistamines of course -cyproheptadine -Pepcid -singular -xolair -cellcept I’m also on Humira only for my rheumatoid arthritis but it seems to do something to combat my crazy mast cells. I don’t know if this exact answers your question but I hope it might help somehow!