Anaphylaxis to Pantoprazole and Omeprazole With Cross-Reactivity to All Proton Pump Inhibitors: Identification of a Safe Alternative

Proton pump inhibitors (PPIs) are widely prescribed for the management of peptic diseases, including gastroesophageal reflux (GER) and gastric ulcers. The risk profile of PPIs is acceptable, and hypersensitivity reactions to PPIs are extremely rare. We present a case in which type I hypersensitivity reactions to all PPIs were confirmed. A 43-year-old woman was admitted to our inpatient clinic with a history of anaphylactic reactions to both pantoprazole and omeprazole. Allergy work-up revealed an IgE-mediated hypersensitivity to all proton pump inhibitors. H2 receptor antagonist famotidine was considered safe after negative results on both the skin prick test (SPT) and oral provocation test (OPT) .