Higher risk of infantile atopic dermatitis from maternal atopy than from paternal atopy.

The risk of infantile atopic dermatitis (AD) posed by maternal atopy and paternal atopy, respectively, were compared in the infants from a birth cohort in whom one of the parents had been designated atopic by skin prick testing. Nineteen with atopic mothers were compared with 20 with atopic fathers. AD, other atopic manifestations and potentially influential factors such as breast-feeding were documented prospectively during the first year in all infants. At 3, 6 and 12 month assessments skin prick sensitivity and total serum IgE concentration were determined. Nine of 19 infants with atopic mothers and two of 20 with atopic fathers had AD (P = 0.023) giving a relative risk of 4.7 (95% confidence interval 2.5 to 9.0). Seven of 19 with atopic mothers and none with atopic fathers had AD with onset before 6 months (P = 0.007). When all types of disease evidence (AD, recurrent wheeze and food reactions) were analysed together no significant difference was apparent between the groups. The two groups were found to be well matched with regard to breast-feeding, time of starting cow's milk, solids and egg, sex, month of birth, parental AD and smoking, race, household pets and neonatal IgE concentration. IgE concentrations at each age and the prevalence of skin prick positivity were similar between the groups. Maternal atopy poses a higher risk for infantile AD and paternal atopy. Whether this may be due to genetic or congenital factors or both is uncertain, but clearly the finding is of relevance in the prediction of allergy in childhood.