Abstract

JM Harris, P Cullinan, HC Williams, P MIlls, S Moffat, C White and AJ Newman
Taylor
Full reference: British Journal of Dermatology 2001; 144: 795-802.

BACKGROUND: Although atopic eczema (AE) is a common disease, little is known about its causes.Objectives: To investigate the role of dietary and environmental factors associated with the development of atopic eczema by the age of 2 years.

DESIGN: A cohort of children was recruited before birth from a consecutive series of newly-pregnant mothers presenting for antenatal care at three general practices in Ashford, Kent, UK. Data up to the age of two were available for 624 (97%) of the original cohort of children. AE was defined using components of the U.K. diagnostic criteria for atopic eczema (AE), maternal report of doctor-diagnosed eczema and maternally reported eczema. Exposures of interest were family history of allergic disease, dietary and breastfeeding patterns, family size and exposure to indoor domestic allergens.

RESULTS: The cumulative prevalence of AE using the U.K. diagnostic criteria was 14% (95% ci 11%, 17%). The prevalence of maternally reported doctor-diagnosed eczema was much higher (31% [27%, 35%]) and almost half (45%) mothers reported that their child had ever had eczema (95% ci [41%, 49%]). The relationship between parental atopy, parental history of allergic disease and the child's eczema was consistently stronger for the mothers than the fathers. There was a marked increase in the prevalence of eczema with increasing maternal education and in less crowded homes, associations that remained significant after controlling for other factors.

CONCLUSIONS: The associations with environmental factors are consistent with the hypothesis that more crowded houses, increased family size and birth order, which possibly increase exposure to infections, may offer protection from subsequent development of eczema.