Proton pump inhibitor-induced subacute cutaneous lupus erythematosus

SUMMARY: BACKGROUND: Drug-induced subacute cutaneous lupus erythematosus (SCLE) has been known in the literature since 1985 and is increasingly recognized. OBJECTIVES: To identify and describe patients with proton pump inhibitor (PPI)-induced SCLE. METHODS: A retrospective medical chart review of patients diagnosed with lupus erythematosus at the Department of Dermatology and Allergy Centre was carried out over a 19-year period. A causality assessment to PPI was performed using the Naranjo probability scale. RESULTS: Twenty-four patients with PPI-induced SCLE were identified (21 women and three men). Nineteen patients were newly identified cases, with a mean age of 61 years. These patients had 24 episodes of PPI-induced SCLE comprising lansoprazole (12), omeprazole (six), esomeprazole (four) and pantoprazole (two). Four patients had multiple episodes and three patients reacted to different PPIs. The incubation period was on average 8 months (range 1 week to 3·5 years) and the resolution period was on average 3 months (range 4 weeks to 8 months). Antinuclear antibodies were positive in 61% of tested patients, most frequently with a speckled pattern. Positive anti-Ro/SSA antibodies were found in 73%, anti-La/SSB antibodies in 33% and antihistone antibodies in 8% of tested patients at the time of the eruption. The skin rash was often widespread with a tendency to bullous lesions and focal skin necrosis. CONCLUSIONS: We present the largest case series of PPI-induced SCLE reported to date, and our patient cohort reveals the lack of attention to this condition. The diagnosis may be suspected on the clinical picture, and most patients have anti-Ro/SSA antibodies, while antihistone antibodies have no value in the diagnostic process. Cross-reactivity can be seen between different PPIs.