Toddlers sensitive to house dust mites at higher risk of developing asthma

Aug 24 2011

Wheezy toddlers who have a sensitivity to house dust mites are more at risk of developing asthma by the age of 12, a University of Melbourne led study has shown.

Children aged one - two years with a family history of allergy, who had a positive skin prick test to house dust mites, had a higher risk of developing asthma later in life. Results showed 75 per cent of these children had asthma at aged 12 compared to 36 per cent of children without a positive skin prick test.

Lead author Dr Caroline Lodge from the University of Melbourne's School of Population Health said the identification of house dust mites as a predictor for asthma in high risk children, is a significant step forward in identifying high risk groups on whom we can trial interventions.

"Our findings provide researchers with a more targeted group of at risk children, for investigating strategies to prevent asthma later in life," she said.

"House dust mite sensitivity amongst wheezy toddlers could be used as a clinical tool to assist parents in understanding the risk of asthma in their children.

"Although currently there is no known intervention to stop asthma developing, identifying children at higher risk may lead to more tailored treatments of wheeze in this high risk group."

The study followed 620 children, with a family history of allergies, from birth to 12 years old.  Researchers tested the children at the ages of one and two years, for single and multiple sensitivity to milk, egg, peanut, rye grass, cat and house hold dust mites and then again at the age of 12 for having asthma.

"We found in the children aged one - two years, that whatever the mix of sensitivity, if their skin reacted to house dust mites they had a higher chance of developing asthma later in life," Dr Lodge said.

"Our study did not show house dust mite caused asthma but it highlighted a strong correlation between sensitivity and more severe wheeze and asthma.

"House dust mites are common in our environment. They are something we have to live with everyday. Previous studies have revealed that efforts to eradicate house dust mites have been ineffective."

The study was published in the Journal of Allergy and Clinical Immunology. Collaborators involved in the study are the Murdoch Childrens Research Institute, Monash University and the Royal Children's Hospital.

The study is part of a broader project to investigate sensitivity and allergy and their link to asthma.