Atopic dermatitis, house dust mite allergy and month of birth.

An analysis of the month of birth in 210 patients with atopic dermatitis and a positive prick test towards the house dust mite (Dermatophagoides pteronyssinus) showed a significantly higher prevalence of birth in the interval May to November when compared with the expected distribution (p less than 0.01). A subdivision of the AD patients due to the concomitant presence of asthma showed no differences as the relative risk was nearly the same in the two subgroups. This observation indicates that a consistent seasonal preference of birth in patients with atopic dermatitis only applies to the skin disease and not to coexistent asthma.