Background: Hypersensitivity reactions due to Proton pump inhibitors (PPIs ) are rare, and
further anaphylaxis to a PPI with cross-reactivity to all commercially available PPIs is very rare.
Objective: To present a case of anaphylaxis to pantoprazole with cross-reactivity to all commercially
Methods: Skin prick tests (SPTs), intradermal tests (IDTs) and oral provocation tests (OPTs) were
performed with available PPIs according to the method described in previous studies.
Results: All tested PPIs except lansoprazole were positive on skin tests either SPT or IDT. The patient
was challenged with lansoprazole at increasing doses (7.5 mg, 15 mg, 30 mg capsule) every 60 minutes
and she reacted with urticaria to 52.5 mg cumulative dose of lansoprazole. She could tolerate ranitidine
and famotidine tablets via OPT.
Conclusion: In our best knowledge, our case was the first case in this regard and that points the
possibility of all cross-reactive pattern in patients with pantoprazole anaphylaxis and the importance of
a thorough drug allergy work-up for finding safe alternatives. H2 receptor antagonists are used as safe
alternatives in cases with PPI hypersensitivity.