Exfoliative erythrodermia induced by pantoprazole.

Although proton pump inhibitors are widely used, allergic reactions to this group of drugs are rarely reported. In this paper we present the case of a patient who developed a delayed reaction to pantoprazole. A 35-year-old female patient complained of generalised erythema with intense itching and desquamation for three weeks before consulting (Fig. 1). The rash was first noticed five days after the initiation of treatment with topical diltiazem, polyethylene glycol 3359 (Milax), Alevian Duo (simethicone/pinaverium bromide) for anal fissuring, and pantoprazole for gastritis. Past medical history disclosed appendectomy, chickenpox, and chronic rhinosinusitis. Physical examination showed xeroderma, widely distributed erythema and generalised desquamation, more pronounced on the hands, and lower limbs (Fig. 2). The diagnosis of exfoliative erythrodermia likely related to drug allergy was made and symptoms resolved completely after treatment with oral prednisone, topical corticosteroids (mometasone furoate and 0.1% methylprednisolone aceponate), and oral antihistamines (desloratadine, cetirizine). No other underlying clinical conditions, including autoimmune, allergic or infectious diseases were present, as deducted from patient questioning and physical examination. Routine laboratory investigations, including haematology, blood chemistry, urine and stool examination were within normal limits. Histopathological examination of the skin was not performed. Six weeks after the first visit patch tests with drugs, with reading after 72 and 96 h, were performed. Milax, Alevian Duo and pantoprazole 10% were applied in white petrolatum. Tests were negative for 2% diltiazem ointment, Alevian Duo and Milax. The test was positive for pantoprazole, showing local erythema and oedema at 72 and 96 h (Fig. 3). Patch tests with all drugs mentioned above were negative in 12 voluntary individuals who did not have a history of drug allergy. Avoidance of pantoprazole and substitution with lanzoprazole were recommended. IgE-mediated allergic reactions to proton pump inhibitors, especially anaphylaxis and urticaria, have been occasionally reported by various investigators. In regard to delayed reactions, Mockenhaupt et al. observed nine Figure 1 Erythrodermic and exfoliative dermatitis in a 35year-old female patient with delayed allergy to pantoprazole.