Allergens prevalent in low-income housing can trigger childhood asthma

• The amount of mouse allergen found in the air in many inner-city homes could be high enough to trigger asthma symptoms in the children who live there, say researchers at the Johns Hopkins Children's Center.
• Their study, published in the February issue of the Journal of Allergy and Clinical Immunology, found more than a quarter of inner-city homes sampled had airborne allergen levels already known to aggravate asthma symptoms in animal research lab workers with mouse allergy.
• "Children living in inner-city homes are continuously exposed to the allergy-causing substance found in mouse urine that is circulating in the air," says Elizabeth Matsui, M.D., a pediatric allergist at the Johns Hopkins Children's Center and lead author of the study.
• "This exposure increases their risk for developing allergic sensitivity to mice, just as it does for laboratory workers who constantly work with rodents."
• Other common household allergens known to affect asthma include proteins shed by cockroaches, dust mites, furry pets and mold, along with tobacco smoke and certain chemicals.
• Once sensitized, such children exposed to airborne mouse allergen at the high levels found in the study may be more likely to experience asthma symptoms, including wheezing or difficulty breathing, which could lead to a full-blown asthma attack or other asthma-related illnesses, Matsui said.
• "Because asthma attacks have the potential to be life-threatening, these findings are of some concern," she adds.
• "One of the best ways parents can manage their child's asthma is to control the home environment and remove any asthma triggers, including mouse allergen," she adds.
• In the study, Matsui and colleagues collected air and dust samples from the bedrooms of 100 inner-city children with asthma and found 84 percent of bedrooms had detectable levels of mouse allergen.