Background Obesity in early childhood is associated with increased risk for and severity of atopic dermatitis (AD).
Objective To determine whether obesity in adulthood is associated with risk of AD.
Methods This was a retrospective case–control study of 2090 adults using questionnaire, height and weight, and skin-prick testing between January 1994 and December 2003.
Results Obesity in adults was associated with increased AD [multinomial logistic regression: adjusted odds ratio (aOR) 1·43, 95% confidence interval (CI) 1·08–1·89; P = 0·01], but not nonatopic dermatitis (aOR 0·59, 95% CI 0·21–1·68; P = 0·32). Obesity was also associated with increased atopic asthma (aOR 1·98, 95% CI 1·47–2·66, P < 0·0001), but not associated with nonatopic asthma (P = 0·20), atopic or nonatopic rhinoconjunctivitis (P = 0·08 and 0·31, respectively), food allergies (P = 0·67 and 0·35, respectively) or atopy (P = 0·40). The association between obesity and AD remained significant even when controlling for history of asthma, rhinoconjunctivitis and food allergies (aOR 1·40, 95% CI 1·05–1·86; P = 0·02) or in subset analyses of subjects with AD alone (aOR 1·96, 95% CI 1·02–3·75; P = 0·04) and with comorbid asthma, rhinoconjunctivitis and/or food allergies (aOR 1·40, 95% CI 1·03–1·91; P = 0·03).
Conclusion Obesity in adulthood is associated with AD. Further studies are warranted to determine if weight loss may prevent or mitigate AD in adults.