Abstract

Background A cross-sectional study was performed in a population-based German sample (n=13 318 children and adolescents aged 3–17) to replicate the recently reported independent association of atopic eczema (AE) and attention-deficit/hyperactivity disorder (ADHD) and to further investigate the role of environmental and behavioural factors.

Methods The odds ratio (OR) was calculated with allergic comorbidity and various environmental factors considered as confounders and sleeping problems hypothesised to act as a potential effect modifier.

Results The lifetime prevalence of AE and ADHD was 14.7% (male 14.4%; female 14.9%) and 4.9% (male 7.8%; female 2.0%), respectively. There was an association between ADHD and AE (OR 1.54; 95% CI 1.24 to 1.93; p<0.001), which was independent of sociodemographic factors, parental smoking, breastfeeding, number of siblings, perinatal health problems, and atopic comorbidity. Further analyses of a subgroup of 6484 children age 3–11 confirmed the hypothesis that the association between AE and ADHD was modified by sleeping problems (interaction effect AE*sleep problems OR 2.02 95% CI 1.03 to 3.97; p=0.04). There was a strong association between AE and ADHD in children with SP (OR 2.67 95% CI 1.51 to 4.71; p=0.001; n=1112), but not in children without SP (OR 1.24 95% CI 0.83 to 1.84; p=0.30; n=5796).

Conclusions ADHD and AE appear to be strongly and independently associated in children with sleeping problems, but not in children without sleeping problems. A substantial part of diagnoses met for ADHD might be engendered by the presence of AE and concomitant sleeping problems.