IgE-mediated allergy to proton pump inhibitors with both delayed and immediate onset

Abstract

Proton pump inhibitors (PPIs) are widely used for the treatment of gastrointestinal diseases. Incidence of drug hypersensitivity reactions (DHRs) to PPIs has been rising, presumably because of their increased consumption. Most DHR are IgE-mediated, with half of the reactions being anaphylactic. We describe the case of a Caucasian 50-year-old female patient referred to our allergy department after 2 episodes of anaphylaxis. The allergy work-up distinguished PPI as a cause of delayed onset (14 hours) and immediate onset (45 minutes) IgE-mediated DHR.

Omeprazole-induced urticaria: A selective hypersensitivity

“…In our case, urticaria occurred four hours after omeprazole intake which is in line with literature. Indeed, immediate hypersensitivity reactions generally occur within a few hours after a dose, even though some case reports of delayed anaphylaxis to PPIs that occur between 2 and 24 hours after the intake of the latter drugs have been described (5,7). The incidence of hypersensitivity to omeprazole, the culprit PPI in our patient, is variable.…”

“…Based on the Naranjo algorithm (4), it is probable that the urticaria was induced by omeprazole (Naranjo's score -5). IgE-mediated reactions are the most frequently reported hypersensitivity reactions to PPIs (5). Urticaria was the most common clinical presentation in patients with immediate hypersensitivity reactions to PPIs after anaphylaxis (6).…”