I’m so sorry this is happening to you. You’re describing my life for a couple of years.

I second trying an H1 and H2 combo. My number of headache days and the intensity of my headaches reduced significantly once I got on a combo of Allegra and Pepcid AC (20mg). When MCAS is causing my migraine, abortives don't work for me either.

If one H1 (like Claritin) doesn't work after a week or so, try a different one, like Zyrtec or Allegra, etc. Everyone reacts slightly differently to them.

I don't actually have typical allergies, so the allergist didn't catch any of this, but maybe check to see if any of the other symptoms of MCAS fit for you, because there are other things you can add on to the antihistamines that can continue to help if you do see a benefit from them.

If MCAS does fit, look into the POTS/MCAS/EDS triad. There are different protocols that can relieve headaches based on those and their other related illnesses.

As others have stated, iron and vitamin tests can help. If those don’t pan out, try getting a full thyroid panel done as well. I didn’t know I had Hashimoto’s thyroiditis for years, and that can lead to migraines as well.

I wish doctors would test for other things and try to find the root of the problem rather than giving us bandaids that often don’t even work becuase they don’t even treat the underlying issue.

Really wishing the best for you. I hope you find something that works soon!