A 35-year-old woman with systemic mastocytosis experiences recurrent episodes of flushing, pruritus, and gastric hypersecretion due to excessive histamine release. Which combination of drugs best addresses both the cutaneous and gastric symptoms simultaneously?

• A H1 blocker alone (e.g., cetirizine)
• B H2 blocker alone (e.g., ranitidine)
• C Proton pump inhibitor plus a mast cell stabiliser only
• D Combined H1 blocker and H2 blocker ✓

Explanation

Histamine produces cutaneous effects (pruritus, urticaria, flushing) through H1 receptors, blocked by agents such as cetirizine or fexofenadine, and gastric acid hypersecretion through H2 receptors, blocked by ranitidine or famotidine. In mastocytosis, excessive histamine release activates both receptor types simultaneously, so blocking only one receptor subtype leaves the other's effects uncontrolled. Combined H1 plus H2 blockade provides comprehensive symptom relief. A proton pump inhibitor controls acid but does not address skin symptoms, and mast cell stabilisers are useful adjuncts rather than replacements for receptor blockade.

Reference: KD Tripathi, Essentials of Medical Pharmacology, 8th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.