Cockroaches a Health Threat to Older, Urban Asthmatics

The bugs' allergens trigger increased breathing problems

FRIDAY, Nov. 22, 2002 (HealthDayNews) -- Cockroaches may be more than a nuisance to many city dwellers. The elusive insects also may be a danger to their health.

Researchers say cockroach allergens may be a major contributor to the health problems of urban asthma sufferers of all ages, now that a new study is shining light on the extent of the threat to people aged 60 and older.

The study by researchers at New York University School of Medicine shows cockroach allergens are a leading cause of increased breathing problems for nearly half of elderly urban asthma sufferers.

"Research has shown cockroach as the most significant allergen in children and adults with asthma. However, there is very little known about asthma and the elderly," says Dr. Linda Rogers, lead author of the study. "This study suggests that cockroach is a highly significant allergen to all age groups."

Dr. Dennis Ownby, an allergist at the Medical College of Georgia, says he's not totally surprised by the study, since cockroaches are probably the leading allergen for people living in urban areas. However, he adds, he was struck by the study's finding that so many older asthma sufferers are still allergic to cockroaches.

"I think there's a bias among physicians that while allergies may contribute to the severity of asthma in children and young adults, we typically think that among older adults, there's almost no relationship between allergy and the severity of asthma," Ownby says. "There's kind of a general presumption that the older you get, the less likely allergy plays a role in your asthma."

"It's generally accepted cockroach is a very important allergen in the inner city, it's just kind of surprising in this 60 and up age group to see that half of them are still sensitive to cockroach and that it does seem to make a real difference to their asthma," he says.

Rogers, an assistant professor of medicine at New York University's School of Medicine and an attending physician at Bellevue Hospital Asthma Clinic, had a similar reaction to her study's findings because there has been a perception in the medical community that older asthmatics generally do not have allergies.

"We're actually surprised by how much allergy there was in our elderly population," Rogers says.

The study sends the message that older asthmatics in urban areas, as is the case with any city dweller suffering from the disease, should try to take steps to better manage their environments, including trying to get rid of cockroaches in their midst, Rogers says.

The problem, as people who have had cockroaches scurrying around their homes know, is that it's not so simple.

"Easier said than done," Rogers admits.

She points to a study several years ago on the link between cockroach allergies and increased visits to the emergency room for city children with asthma.

"They went into a number of buildings and tried to eradicate [the cockroach problem], but what they found is you get rid of them in one apartment and they come in next door essentially," Rogers says. "So even with very extensive measures, it's difficult to get rid of them."

The NYU study, which is published in the new issue of Chest, involved 45 non-smoking asthma patients evaluated at Bellevue Hospital Asthma Clinic between 1991 and 1998.

Tests showed that 53 percent of the patients were sensitized to at least one indoor allergen and 20 percent were sensitized to at least one outdoor allergen.

The leading indoor allergen was the cockroach. Forty percent of the subjects in study were allergic to the nocturnal insect.

The patients allergic to indoor allergens suffered decreased lung function, but there was no correlation between pulmonary function and outdoor allergens.

More than 17 million people in the United States have asthma, and more than 5,000 people die from the disease each year, according to the American Academy of Asthma, Allergy and Immunology.

Asthma is a chronic disease in which air flow to and from the lungs may be blocked by muscle squeezing, swelling and excess mucus.

What To Do

To learn more about asthma and allergies, visit the American Academy of Allergy, Asthma and Immunology or the Asthma and Allergy Foundation of America. To learn more than you probably want to know about cockroaches, try this PBS site.

SOURCES: Linda Rogers, M.D., assistant professor, medicine, New York University School of Medicine, and attending physician, Bellevue Hospital Asthma Clinic, both in New York City; Dennis Ownby, M.D., allergist, Medical College of Georgia, Augusta; November 2002 Chest
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