Study reveals cockroach allergen worsens asthma symptoms

• "These data confirm that cockroach allergen is the primary contributor to childhood asthma in inner-city home environments," says Kenneth Olden, PhD, director of the National Institute of Environmental Health Sciences (NIEHS).
• The study, published in the March 2005 issue of The Journal of Allergy and Clinical Immunology, is the first large-scale study to show marked geographic differences in allergen exposure and sensitivity in inner-city children.
• Most homes in Northeastern U.S. cities had high levels of cockroach allergen, while those in the South and Northwest had dust mite allergen levels in ranges known to exacerbate asthma symptoms.
• Other measures include repairing leaky faucets, frequent vacuuming of carpeted areas and damp-mopping of hard floors, and regular cleaning of countertops and other surfaces.
• "We found that a majority of homes in Chicago, New York City and the Bronx had cockroach allergen levels high enough to trigger asthma symptoms, while a majority of homes in Dallas and Seattle had dust mite allergen levels above the asthma symptom threshold," says Rebecca Gruchalla, MD, associate professor of internal medicine and pediatrics at the University of Texas Southwestern Medical Center and lead author of the study.
• While cockroach allergen exposure did produce an increase in asthma symptoms, researchers did not find an increase in asthma symptoms as a result of exposure to dust mite and pet dander.
• "Children who tested positive for, and were exposed to, cockroach allergen experienced a significant increase in the number of days with cough, wheezing, and chest tightness, number of nights with interrupted sleep, number of missed school days, and number of times they had to slow down or discontinue their play activity," says Gruchalla.
• While cockroaches are primarily attracted to water sources and food debris, house dust mites, microscopic spider-like creatures that feed on flakes of human skin, reside in bedding, carpets, upholstery, draperies, and other "dust traps."
• The children, ages 5 to 11, were given skin tests for sensitivity to cockroach and dust mite allergens, pet dander, and mold.