A familial tendency toward skin sensitivity to ragweed pollen

Abstract

A study was undertaken to establish whether or not the ability to develop skin-sensitizing antibodies to ragweed pollen is familial. The frequency of positive intradermal skin tests to ragweed pollen extract was compared in the parents and sibs of children with ragweed hay fever and positive skin tests and the parents and sibs of children without ragweed hay fever and with negative skin tests, selected without reference to a family history of allergy. The frequency of positive skin tests to ragweed pollen extract was found to be higher in the sibs of children with positive skin tests and symptoms of ragweed hay fever (28.0 per cent) than it was in sibs of children with negative skin tests and no ragweed fever (4.8 per cent). The frequency of positive skin tests to ragweed pollen extract was higher in the sibs of children with positive skin tests and symptoms of ragweed hay fever when at least one parent had a positive skin test (48.5 per cent) than it was when neither parent had a positive skin test (14.3 per cent). These findings clearly demonstrate that the ability to form skin-sensitizing antibodies to ragweed pollen is familial and probably genetically determined. The ability to develop a positive skin test to grass pollen extract was also found to be familial.