Family size, childhood infections and atopic diseases. The Aberdeen WHEASE Group

Abstract

These data add to the accumulating evidence that membership of a large sibship confers some protection against atopic disease. This does not appear to be explained by the common childhood infections which show conflicting relationships with atopic disease, in that measles may have some protective effect against asthma but the more infections a child has had, the more likely he or she is to have atopic disease. The explanation of the sibship effect is likely to lie elsewhere and the fall in common childhood infections is unlikely to explain the rise in atopic disease.