Histamine
Primary vasoactive mediator causing flushing, pruritus, GI symptoms
- Expression
- Elevated (released during degranulation)
- Evidence level
- established
- Targeted by
- H1 antihistamines, H2 antihistamines
Role in pathogenesis
Histamine is a key preformed mediator stored in mast cell granules. Drives flushing (H1/H2), pruritus (H1), gastric acid hypersecretion (H2), and contributes to anaphylaxis. Targeted by H1 and H2 antihistamines, the first-line therapy for mediator symptoms.