Background/Purpose: Drug induced subacute cutaneous lupus erythematosus has rarely been described. There is a growing literature reporting the association between proton pump inhibitor use and subacute cutaneous lupus erythematosus (SCLE). We aim to describe the clinical characteristics of a cohort of patients with proton pump inhibitor induced subacute cutaneous lupus erythematosus, their clinical course and treatment options.

Methods: We retrospectively reviewed twelve patients with proton pump inhibitor induced subacute cutaneous lupus erythematosus at the Louise Coote Lupus Unit. Clinical details recorded included presence of underlying systemic lupus erythematosus (SLE) and SCLE, extent of cutaneous involvement, time to presentation, type of proton pump inhibitor and dosage, histological characteristics, immunological characteristics, treatment and time to resolution.

Results: There were 12 patients of whom 10 were female (83%). Eleven patients were Caucasians (92%). The median age at diagnosis was 61 years (range 37-71). Nine patients (75%) had underlying SLE. In this subgroup, only one patient had SCLE as part of their initial SLE presentation. Patients with coexisting SLE were younger with a median age of 53 years compared to patients without coexisting SLE. There were 8 patients with omeprazole, 3 patients with lansoprazole and 1 patient with pantoprazole induced SCLE.

All patients developed typical SCLE lesions clinically. The extent of SCLE was widespread involving the sun- exposed areas of the trunk, upper extremities and the lower limbs in 50% of the patients. Eleven (92%) demonstrated antinuclear antibody positivity and 9 patients (75%) anti-Ro (SS-A) antibody positivity. Seven patients underwent a skin biopsy and 6 patients had histological results in keeping with SCLE. The median time to presentation was 12 months (range 3 weeks -10 years) and the median resolution period was 19 days (range 3 days- 2 months). Proton pump inhibitors were stopped in all patients. Five patients (42%) received concurrent oral corticosteroids and 3 patients (25%) were newly initiated on hydroxychloroquine. Two patients received adjunctive topical therapy including topical steroids alone or in combination with topical tacrolimus. Four patients were re-exposed to proton pump inhibitors and 3 experienced a similar SCLE flare, which resolved following cessation of the proton pump inhibitor. (Table 1)

Conclusion: Proton pump inhibitor induced subacute cutaneous lupus may be commonly associated with anti-Ro (SS-A) antibody and this is likely a class effect with all proton pump inhibitors. In July 2015, the European Medicines Agency issued a warning that SCLE is likely to be a class effect for proton pump inhibitors. We recommend judicious use of proton pump inhibitors particularly in SLE patients with anti-Ro (SS-A) antibody positivity.

Table 1: Clinical characteristics and outcome of patients with proton pump inhibitor induced SCLE