Risk factors for atopic dermatitis in infants at high risk of allergy: the PIAMA study

Background It has been suggested that the period immediately after birth is a sensitive period for the development of atopic disease. Objective We investigated whether birth characteristics and environmental factors are associated with the development of atopic dermatitis in the first year of life. Methods Seventy-six children with and 228 without atopic dermatitis, all children of mothers with respiratory allergy or asthma (PIAMA birth cohort study) were included in the study. Atopic dermatitis was defined as a positive history of an itchy skin condition with at least two of the following characteristics: visible dermatitis, history of outer arms/leg involvement, or general dry skin. Multiple logistic regression analysis was performed to study the independent effects of various risk factors. Results A birth weight greater than or equal to4000 g compared to 3000 - 4000 g was a significant risk factor for atopic dermatitis ( odds ratio (OR) = 2.4; 95% CI: 1.1 - 5.1) as was day care attendance (OR = 2.9; 95% CI: 1.5 - 5.9). Exclusive breastfeeding in the first 3 months was negatively associated with atopic dermatitis (OR = 0.6; 95% CI: 0.3 - 1.2), especially with visible dermatitis (OR = 0.4; 95% CI: 0.2-1.0). Gender, gestational age, the presence of siblings or pets, and parental smoking were not significantly associated with atopic dermatitis. Conclusion This study shows that a high birth weight and day care attendance increase the risk of atopic dermatitis in the first year of life, while exclusive breastfeeding is a protective factor when dermatitis is found on inspection.