Late hypersensitivity to omeprazole and other proton pump inhibitors

A 63 year-old woman presented with a persistent, red, papular, itching skin eruption localised on the face, right shoulder and the right upper member. The evolution was longer than ten years with a permanent progressive diffuse facial burning sensation and unaesthetic aspect despite topical antibiotic and anti-inflammatory treatments. The clinical and the histological diagnosis corresponded to prurigo. She was treated by omeprazole for gastric reflux since more than ten years, and she had a viral C hepatitis. The relationship between prurigo and omeprazole was evidenced by the complete resolution of symptoms after the drug's interruption and the recurrence after the omeprazole re-introduction. The immediate and late skin tests were negative for the tested drugs. Clinical cross-reactivity was observed with pantoprazole and lansoprazole; this suggested a late hypersensitivity to drugs of the proton pump inhibitors class. To our knowledge, it is the first case of prurigo induced by these drugs.