The “TMS For A Cure” website has this great page on medications to treat mast cell disorders.
A few notes from the article I linked to:
This post discusses medications used to treat MCAS. Doses listed are taken directly from “Presentation, diagnosis and management of mast cell activation syndrome” by Lawrence B. Afrin. These doses are general recommendations. Medication should always be taken under the direction of a provider who knows you and your case personally.