Allergen exposure in inner cities varies throughout the U.S.

New research from the Journal of Allergy & Clinical Immunology

Inner city children with asthma are exposed to significantly different levels of indoor allergens depending on the area of the country and type of home in which they live. These findings are featured in the March 2005 Journal of Allergy & Clinical Immunology (JACI).
Exposure to major indoor allergens, such as dust mites, pets and cockroaches, contribute to the increasing prevalence of asthma in children living in inner city environments. Rebecca S. Gruchalla, MD, PhD, FAAAAI, and researchers with the Inner City Asthma Study examined the relationship between indoor allergen exposure, skin test reactivity and asthma symptoms in children living in inner cities located in different geographic locations across the United States. Skin tests were administered to 937 children with moderate to severe asthma.

Allergen levels were found to vary dramatically across the inner cities studied. Among the findings:

• Cockroach exposure and sensitivity were highest in the Northeast, with the highest levels found in New York City.
• Levels of dust mite allergen were the highest in the South and Northwest, particularly in Seattle and Dallas.
• Cockroach allergen levels were significantly higher in high rise apartments.
• Dust mite levels were significantly higher in detached homes.

In addition, researchers discovered cockroach allergen had a greater impact on asthma than dust mite allergen. The children whose asthma symptoms were triggered by exposure to cockroach allergen displayed more asthma symptoms, missed more school, and made more unscheduled trips to their doctor because of their asthma.

While researchers did not find this kind of relationship between dust mites and asthma, their findings do suggest that children allergic and exposed to dog and cat allergen have more unscheduled asthma healthcare visits than children not exposed and/or who are not allergic.

The Inner City Asthma Study demonstrated that inner city children with asthma are exposed to significantly different levels of indoor allergens depending on what area of the country and type of home they live in. Their findings also suggest that cockroaches have the greatest effect on asthma morbidity among children living in inner-city environments.