The epidemiology of asthma and hay fever in a total community, Tecumseh, Michigan: II. The relationship between asthma and hay fever

Abstract

The clinical experience of allergists suggests that many persons with hay fever may develop asthma if not treated with allergenic extracts. The question has been raised that the experience of specialists may be weighted with the more serious cases of hay fever and therefore lead to a distorted picture of the natural history. While initial epidemiological data from this study of a total community are in keeping with clinical experience in indicating a frequent correlation between asthma and hay fever, they do not suggest that this relationship is dominated by hay fever leading to asthma: 75 per cent of persons having a history of both asthma and hay fever had either asthma alone initially or the two appeared within the same year of age; of all persons with hay fever who were at risk to develop asthma, this subsequently occurred in only 5 to 10 per cent. It is unlikely that injection therapy has appreciably altered the tendency for hay fever to be complicated by asthma in this population. The data also imply that allergists may be exposed to a segment of the hay fever population in which the prevalence of asthma is disproportionately high.