Age at onset and persistence of eczema are related to subsequent risk of asthma and hay fever from birth to 18years of age.

Abstract

Few studies have simultaneously addressed the importance of age of onset and persistence of eczema for the subsequent development of asthma and hay fever, particularly into early adulthood. A high-risk birth cohort was recruited comprising 620 infants, who were then followed up frequently until 2years of age, annually from age 3 to 7, then at 12 and 18years, to document any episodes of eczema, current asthma, and hay fever. The generalized estimation equationtechnique was used to examine asthma and hay fever outcomes at 6 (n=325), 12 (n=248) and 18 (n=240) years, when there was consistency of associations across the follow-ups. Very early-onset persistent (onset <6months, still present from 2 to 5years) eczema was related to current asthma (adjusted OR=3.2 [95% CI=1.7-6.1]), as was very early-onset remitting eczema (onset <6months but not present from 2-5years, OR=2.7, 95% CI=1.0-7.2) and early-onset persistent eczema (onset from 6-24months, OR=2.3, 95% CI=1.2-4.7). Late-onset eczema (commenced from 2-5years) was associated with increased risk of asthma at 12years (OR=3.0, 95% CI=1.1-8.2) but not at age 6years. Only very early-onset persistent eczema was associated with increased risk of hay fever (aOR=2.4, 95% CI=1.4-4.1). Eczema which commences in early infancy and persists into toddler years is strongly associated with asthma, and to a lesser extent hay fever, in high-risk children. If these associations are causal, prevention of early-life eczema might reduce the risk of respiratory allergy.