O10 Risk factors for incident and recurrent erythrodermic psoriasis: cohort analyses from the British Association of Dermatologists Biologics and Immunomodulators Register

Abstract

Erythrodermic psoriasis (EP) is a severe variant of psoriasis affecting > 90% of the skin. It is a morphologically distinct phenotype, with worse outcomes than plaque psoriasis. Risk factors for EP are poorly understood. This study aimed to identify demographic, lifestyle and clinical determinants of new-onset EP or recurrent EP. Data from the British Association of Dermatologists Biologics and Immunomodulators Register (BADBIR) were analysed. All participants with baseline registration data were included. Risk of incident (new-onset) EP was investigated using multivariable Cox models, excluding those with a history of EP at baseline. This was repeated for recurrent EP, including only patients with a history of EP at registration. Confounders were determined by directed acyclic graphs. Time was counted from study registration until the date of the first EP event, last follow-up or death. Relationships between continuous variables and EP were modelled using restricted cubic splines to allow for nonlinearity. Effect estimates are given as the adjusted hazard ratio (HR) and 95% confidence interval (CI). Of the 16 206 included participants, 2518 had prevalent EP, 52 developed incident EP and 70 developed recurrent EP. Incident EP was associated with weekly alcohol consumption (adjusted HR 1.02 per unit, 95% CI 1.00–1.03), palmoplantar pustulosis (3.79, 1.13–12.7) and asthma (2.85, 1.48–5.49), and nonlinearly with baseline Psoriasis Area and Severity Index (PASI), age of onset and disease duration (P < 0.05). Recurrent EP was associated with alcohol consumption (adjusted HR 1.01, 95% CI 1.00–1.02), PASI (1.05, 1.03–1.07), disease duration (0.97, 0.95–0.99), age of onset (1.01, 1.00–1.03) and depression (1.71, 1.03–2.85). There was a borderline association with psoriatic arthritis (1.65, 0.98–2.75). Incident and recurrent EP have overlapping and divergent risk factors, which could be used for risk stratification. Associations between incident EP and palmoplantar pustulosis or asthma could implicate immunological heterogeneity in the development of EP. Research is required to elucidate the mechanisms of these associations, which could inform strategies to improve EP management.