The risk of venous thromboembolism in atopic dermatitis: A matched cohort analysis in UK primary care.

Abstract

Atopic dermatitis (AD) is a common chronic inflammatory skin condition. Whilst other chronic inflammatory conditions are associated with increased risk of venous thromboembolism (VTE), associations between AD and VTE have not been established. We examined whether AD is associated with increased risk of VTE in a population-based study. Electronic health records were extracted from UK general practices contributing to Optimum Patient Care Research Database. All adults with AD over 2010-2020 identified (n=150,975), and were age and sex matched with unaffected controls (n=603,770). Risk of VTE, consisting of pulmonary embolism (PE) or deep vein thrombosis (DVT), were compared in people with AD versus controls using Cox proportional hazard models. PE and DVT were examined separately as secondary outcomes. 150,975 adults with active AD were identified and matched with 603,770 unaffected controls. During the study, 2,576 of the people with active AD and 7,563 of the matched controls developed VTE. Individuals with AD had a higher risk of VTE than controls (adjusted hazard ratio [aHR] 1.17, 95% Confidence Interval [CI] 1.12-1.22). When assessing VTE components, AD was associated with a higher risk of DVT (aHR 1.30, 95%CI 1.23-1.37) but not PE (aHR 0.94, 95%CI 0.87-1.02). VTE risk was greater in older people with AD (≥65 years: aHR 1.22, 95%CI 1.15-1.29; 45-65 years: aHR 1.15, 95%CI 1.05-1.26; <45 years: aHR 1.07, 95%CI 0.97-1.19) and those with obesity (BMI≥30: aHR 1.25, 95%CI 1.12-1.39; BMI <30: aHR 1.08, 95%CI 1.01-1.15). Risk was broadly consistent across mild, moderate or severe AD. AD is associated with a small increase in risk of VTE and DVT, with no increase in risk of PE. The magnitude of this risk increase is modest in younger people, and those without obesity.