1. Introduction
Post-anaphylactic mast cell anergy defines a state of mast cell unresponsiveness following massive activation. It is manifested by a loss of cutaneous reactivity to skin tests, and has been described in several series1, 2 and clinical cases3, 4, 5, 6 in the context of anaphylaxis to hymenoptera venoms and perioperative anaphylaxis. Current recommendations by allergology societies indicate diagnostic skin testing between 4 and 8 weeks7, 8 after a severe hypersensitivity reaction to avoid false negative results. The mechanisms involved in this phenomenon are incompletely understood and implicate mast cells mediators depletion.
We report a case of mast cell anergy which enabled a patient to tolerate accidental reintroduction of amoxicillin, despite having presented with intraoperative anaphylactic shock to amoxicillin 3 days earlier.