Association between obesity and atopic dermatitis in childhood: a case-control study.

BACKGROUND: Obesity in children is associated with increased asthma and atopy.

OBJECTIVE: We sought to determine whether obesity in childhood or adolescence increases the risk of atopic dermatitis.

METHODS: This retrospective, practice-based, case-control study randomly sampled 414 children and adolescents (age, 1-21 years) with atopic dermatitis between January 2000 and December 2007 and 828 randomly sampled healthy control subjects. Information was obtained from an electronic medical record. Observations were made before the a priori hypothesis.

RESULTS: Obesity in children is associated with increased atopic dermatitis (conditional logistic regression: odds ratio, 2.00; 95% CI, 1.22-3.26; P = .006). These atopic dermatitis-predisposing effects are found when obesity started by less than 2 years of age (adjusted odds ratio [aOR], 15.10; 95% CI, 1.51-151.21; P = .02) and 2 to 5 years (aOR, 2.58; 95% CI, 1.24-5.41; P = .01) but not greater than 5 years (aOR, 1.32; 95% CI, 0.66-2.64; P = .43) and when obesity was prolonged for 2.5 to 5 years (aOR, 2.64; 95% CI, 1.13-6.18; P = .03) and greater than 5 years (aOR, 3.40; 95% CI, 1.34-8.63; P = 0.01). Obesity is associated with more severe atopic dermatitis (ordinal logistic regression: aOR, 2.37; 95% CI, 1.24-5.37; P = .01). Obese children who eventually have atopic dermatitis require more frequent pediatrician visits for the management of atopic dermatitis (ordinal logistic regression: aOR, 2.22; 95% CI, 1.12-4.50; P = .03).

CONCLUSION: Prolonged obesity in early childhood is a risk factor for atopic dermatitis. Weight loss might be an important approach for the prevention and treatment of atopic dermatitis in children.