D1.271 - Bovine gelatine-induced anaphylaxis brought on by eating beef, sweets containing gelatin, and medications

We report a case of a 40-year-old woman who was referred to our clinic to identify the responsible antigen of anaphylaxis. The patient had presented with a 10-year history of episodes of anaphylaxis (flush, edema, urticaria, nausea, vomiting, syncope) after consuming beef meat or beef soup. Later on, she developed several episodes of anaphylaxis after eating different kinds of gelatine-containing sweets. The most severe anaphylactic reaction with hypotension and syncope started < 1 hour after ingestion of a drug, gelatin-containing capsule of ibuprofen. Elevation of serum tryptase after the reaction was detected. All specific IgE antibodies measured by ImmunoCAP were negative, including alpha-gal, except for bovine gelatine. Positive reactions to cooked beef meat and to gelatin containing sweet gums were found using prick-to-prick skin testing. Additionally, we used purified bovine gelatine for BAT, and the results were positive. Gelatin, a product obtained by the partial hydrolysis of collagen, is widely used in foods, pharmaceuticals, and drugs. However, gelatin allergy to foods was thought to be rare. This rare allergen is often overlooked and, therefore, can lead to misdiagnosis of idiopathic cases. Understanding this uncommon trigger is crucial for clinicians to ensure the exact diagnosis and reliable management of the patient.