DELAYED ANAPHYLAXIS TO SHRIMP EXPOSURE: IS THIS A THING, AND WHO IS AT RISK?

Abstract

<h3>Introduction</h3> Anaphylaxis is a systemic hypersensitivity reaction which is rapid in onset. Delayed anaphylaxis from food ingestion, (ie > 2hrs) is rare. <h3>Case Description</h3> A 17 year old female, previously tolerant to shrimp, experienced a documented delayed anaphylaxis 6 hours following ingestion of shrimp. Shrimp ingestion occurred at 21:30 without incident. The patient felt otherwise well and retired to sleep. At 03:40 the patient awoke to systemic pruritus and full body urticaria with an episode of brief loss of consciousness. She was taken to ER. There the patient experienced nausea, angioedema, and dyspnea. The patient received 0.5 mg IM epinephrine at 06:17 and monitored. At 07:55, 10 mg cetirizine was given to treat persistent pruritus. Discharge was at 10:30 on cetirizine without evidence of a biphasic anaphylaxis. A previous milder reaction to shrimp occurred a few weeks earlier. Skin prick testing (SPT) confirmed allergy House Dust Mite (HDM) (17mm) to D. Farinae and D. Pteronyssinus. Shrimp allergen extract was negative; however, prick-to-prick testing to shrimp was positive to raw shrimp 7mm and cooked shrimp 5mm with 3mm to histamine control. <h3>Discussion</h3> HDM and shrimp share the major muscle muscle allergen tropomyosin. In this case, presentation of shrimp tropomyosin leading to anaphylaxis was delayed, suspected from the digestive process of the meal, in a child previously tolerant to shrimp. This case highlights the need to extend the window of anaphylaxis investigation to 6 hours in patients cross-sensitized to tropomyosin from HDM DF-DP and shrimp ingestion.