Drug fever due to a single dose of pantoprazole.

Although proton pump inhibitors (PPI) are generally well tolerated, with most adverse effects being minor and self-limiting, there are singular reports on hypersensitivity immune reactions triggered by a PPI or its metabolites. Here we report a case of acute drug-induced fever with leukocytosis and a transient increase in CRP due to pantoprazole. This was apparently an idiosyncratic reaction (inflammatory fever), showing no cross-sensitivity towards esomeprazole.