title: Nine cases of omeprazole allergy: cross-reactivity between proton pump inhibitors.
abstract: Although rare, anaphylactic reactions induced by proton pump inhibitors have been reported. The presence of cross-reactivity between different members of the group is not clear. We studied 9 patients with adverse reactions to omeprazole. Clinical symptoms appeared immediately in 8 patients and after 4 hours in 1. Symptoms ranged from urticaria/angioedema in 7 cases to anaphylaxis in 2 cases. Skin prick tests and oral controlled challenge tests with omeprazole, lansoprazole, and pantoprazole were performed. Skin prick or intradermal tests with omeprazole were positive in 8 patients. Four were also positive to pantoprazole. Prick tests with lansoprazole were always negative. Lansoprazole was administered to all 9 patients, with good tolerance in 8. Only 3 patients were challenged with pantoprazole and developed widespread urticaria. We present 9 patients with immunoglobulin E-mediated allergy to omeprazole. In most of our cases, lansoprazole proved to be a good alternative treatment.
authors.affiliation: Department of Allergy, Hospital San Pedro/San Millán, Logroño, Spain. tlobera@riojasalud.es
authors.forename: T
authors.initials: T
authors.lastname: Lobera
authors.forename: B
authors.initials: B
authors.lastname: Navarro
authors.forename: M D
authors.initials: MD
authors.lastname: Del Pozo
authors.forename: I
authors.initials: I
authors.lastname: González
authors.forename: A
authors.initials: A
authors.lastname: Blasco
authors.forename: R
authors.initials: R
authors.lastname: Escudero
authors.forename: M
authors.initials: M
authors.lastname: Venturini
authors.forename: E
authors.initials: E
authors.lastname: Alarcón
mesh_terms: D000328:Adult; D000707:Anaphylaxis / Q000139:chemically induced* / Q000276:immunology; D003429:Cross Reactions / Q000276:immunology; D004342:Drug Hypersensitivity / Q000209:etiology* / Q000276:immunology; D005260:Female; D006801:Humans; D008875:Middle Aged; D009853:Omeprazole / Q000009:adverse effects* / Q000276:immunology; D054328:Proton Pump Inhibitors / Q000009:adverse effects* / Q000276:immunology; D012882:Skin Tests
chemical_list: D054328:Proton Pump Inhibitors; D009853:Omeprazole