A rise in allergic reactions to house dust mites and grass is likely to be contributing to a significant increase in the number of WA men and women being diagnosed with asthma, according to new research.
Results from the world-renowned Busselton Health Study show almost one in five WA men and women are diagnosed with asthma - triple the rate seen 30 years ago.
Researchers said while the trend could be linked partly to doctors becoming better at diagnosing respiratory problems such as asthma, it was also likely to be associated with a corresponding rise in allergies over time.
The results from more than 2700 men and women came from the most recent survey, carried out in 2007.
Dr Michael Hunter, who co-ordinated the study, said the increase in asthma rates was significant, up from 6 per cent to 19 per cent, and associated with changes in symptoms such as wheezing and chesty coughing but not in lung function.
One of the study investigators, clinical associate professor Alan James, said: "We tested skin reactions to common allergens such as house dust mite and grasses in 1981, 1990 and 2007 and we found that in adults between the ages of 19 and 54 there was a significant increase in the percentage of people who had positive skin responses."