Lansoprazole as an uncommon cause of anaphylaxis: What to give next?

Proton pump inhibitors (PPIs) are one of the most prescribed drugs worldwide. Anaphylactic reactions of PPIs are rare; however, several cases have been reported. Here, we report a rare case of anaphylaxis that occurred immediately following lansoprazole intake. Following the successful management in the emergency department, skin prick and oral controlled challenge tests were performed to evaluate cross-reactivity. Thereafter, lansoprazole was switched to pantoprazole, which was well tolerated. Skin prick and oral controlled challenge tests can be performed for determining the cross-reactivity of PPIs to prevent adverse reactions.