A Case Report on Rabeprazole Desensitization for a Patient With Barrett's Esophagus and Anaphylaxis to Multiple Proton Pump Inhibitors.

We report the case of a 58-year-old male patient with Barrett's esophagus who experienced anaphylaxis following the administration of omeprazole and esomeprazole. The patient was successfully desensitized using rabeprazole despite also being sensitized to rabeprazole. Approximately seven years prior, the patient developed generalized urticaria, angioedema, respiratory distress, and loss of consciousness after taking omeprazole, necessitating emergency medical intervention. One year ago, the patient underwent a drug allergy workup with 20 mg of esomeprazole under our supervision at the clinic. As the prick test was negative, oral provocation with 1/64 of the full dose of esomeprazole (0.31 mg) was performed. However, a couple of hours after administration, the patient developed angioedema, urticaria, and shortness of breath, which led to hospitalization. Given the clinical necessity for proton pump inhibitor (PPI) therapy due to Barrett's esophagus, as recommended by a gastroenterologist, desensitization to rabeprazole 20 mg was initiated in a hospital setting, adhering to established international protocols. Prior to the desensitization, the patient's sensitivity to rabeprazole was confirmed through skin tests. The desensitization procedure was successful. In conclusion, while omeprazole and esomeprazole have a high potential for cross-reactivity due to their structural similarity, rabeprazole may be a viable alternative, though hypersensitivity to rabeprazole should not be ruled out. This case highlights the necessity of considering cross-reactivity in PPI hypersensitivity and underscores the utility of skin tests prior to provocation. When no alternative PPI treatment options are available, a PPI desensitization protocol may be successfully implemented.