Being allergic to dogs or cats may worsen your ragweed allergies, according to a study from Queen's University.

Researchers found that people with pet allergies often develop ragweed allergy symptoms more quickly than others. But the study also suggests that once allergy season is in full swing, those symptom differences subside.

The team, led by Anne Ellis, an assistant professor in the departments of medicine and microbiology & immunology, exposed 123 participants to ragweed, and noted that pet allergy sufferers reported symptoms differently than their non-animal allergic counterparts. Dust mite allergic patients also developed symptoms more quickly after ragweed exposure.

"The study results helped us develop a theory of 'pre-priming'," says Dr. Ellis. "If you have ongoing symptoms from perennial allergies, as soon as you add another allergen into the mix your symptoms develop much faster, and you may have a harder time dealing with it than others."

Dr. Ellis says that ideally patients with animal allergies should find alternative homes for their pets, or at least minimize their exposure by not allowing animals access to the bedroom of the allergic individual. This becomes even more important in the case of children suffering from asthma, and could prevent the development of irreversible lung damage due to ongoing allergic inflammation.

The study was conducted at the Environmental Exposure Unit (EEU) at Kingston General Hospital. The results were published in a recent issue of the Annals of Allergy, Asthma & Immunology.

Thirty to fifty percent of the Canadian population will suffer from allergic reactions at some point in their lives. The number is difficult to pinpoint because many allergies go unrecognized or undiagnosed.