Risk of inflammatory dermatoses following COVID-19 infection: a cohort study of 204 241 patients

BACKGROUND: The long-term impact of SARS-CoV-2 infection on inflammatory dermatoses remains incompletely defined. OBJECTIVES: To evaluate the association between COVID-19 infection and a broad range of inflammatory dermatoses. METHODS: In this cohort study, electronic health-record data were analysed for 204 241 patients seen at a tertiary medical centre between March 2020 and May 2023, including 22 368 with confirmed COVID-19 and 181 873 controls with negative testing. Diagnoses of 16 inflammatory dermatoses were extracted from standardized documentation fields and verified diagnostic codes. RESULTS: Elevated risks were observed for atopic dermatitis [incidence rate ratio (IRR) 1.35, 95% confidence interval (CI) 1.25-1.46; P < 0.001], acne vulgaris (IRR 1.53, 95% CI 1.17-1.98; P = 0.002), rosacea (IRR 2.41, 95% CI 1.53-3.66; P < 0.001), alopecia areata (IRR 2.39, 95% CI 1.44-3.80; P < 0.001) and seborrhoeic dermatitis (IRR 1.74; 95% CI 1.29-2.30; P < 0.001). No significant associations were observed for psoriasis, hidradenitis suppurativa, lupus erythematosus, pemphigus or bullous pemphigoid. CONCLUSIONS: COVID-19 infection emerged as a novel risk factor for several inflammatory dermatoses.