Oral Presentations Occupational Airborne Allergic Contact Dermatitis From Omeprazole With Cross-Reactions to Other Proton Pump Inhibitors

Occupational Airborne Allergic Contact Dermatitis From Omeprazole With Cross-Reactions to Other Proton Pump Inhibitors Khuzama Al-Falah, Jordana Schachter, MD, and Denis Sasseville Author Affiliations: McGill University Health Centre, Royal Victoria Hospital, Montreal, QC, Canada Background: Contact dermatitis from omeprazole and other proton pump inhibitors has rarely been reported. Most cases are airborne and occupational, in workers of the pharmaceutical industry who handle PPI in powder form. Case report: A 44-year-old non-atopic woman and professional horse trainer, was referred for investigation of a pruritic dermatitis of 3 months duration, involving her eyelids, face, neck and forearms. This occurred after giving a racehorse a veterinary omeprazolecontaining paste (GastroGard) as treatment for gastric ulcers. Lesions would appear within hours of treating the horse, and would fade over a few days with topical corticosteroids. Method: The patient was patch tested to 3 concentrations of GastroGard, and to 2 concentrations (10% and 1% in petrolatum, prepared from crushed tablets) of each of the PPIs available for human use in Canada. Result: At D4, the patient had a positive reaction to every agent tested. Patch tests were negative in 5 control subjects. Conclusion: We did not separately test the active ingredient, or the components of the vehicle of each drug. However, our results favor the active ingredient and not the vehicle as the sensitizer. We believe that our case is the first to show broad cross-reactivity among PPIs after cutaneous sensitization.