MRGPRX2 in drug allergy: What we know and what we do not know

Immediate drug hypersensitivity reactions are characterized by a broad spectrum of symptoms, varying from urticaria, angioedema, pruritus, upper and lower respiratory symptoms, gastrointestinal symptoms, and hypotension to anaphylaxis. Mechanistically, these reactions often involve mast cell (MC) degranulation, as reflected by elevated serum tryptase levels.1,2