Cockroaches may Cause Asthma in Inner-City Children

ABSTRACT & COMMENTARY

Synopsis: Exposure to high levels of cockroach allergen may help explain the observed high frequency of asthma-related health problems in these inner-city children.

Source: Rosenstreich DL, et al. The role of cockroach allergy and exposure to cockroach allergen in causing morbidity among inner-city children with asthma. N Engl J Med 1997;336:1356-1363.

There is a high frequency of morbidity due to asthma among inner-city children in the United States. Rosenstreich and associates of the National Cooperative Inner-City Asthma Study measured immediate sensitivity to cockroach, house dust mites, and cat allergens by skin testing 476 4- to 9-year-old inner-city children. Of these children, 36.8% were allergic to cockroach, 34.9% were allergic to dust mite, and 22.7% were allergic to cat allergens. Household dust specimens were collected with vacuum cleaners, and the concentrations of allergens were measured by monoclonal antibody-based ELISA assays. Of the children’s bedrooms, 50.2% had high levels of cockroach allergen, 9.7% had high levels of dust mite allergens, and 12.7% had high levels of cat allergen. Children who were both allergic to cockroach allergen and exposed to high levels of this allergen had significantly more hospitalizations and unscheduled medical visits for asthma per year. They also had more days of wheezing, missed school days, and nights with lost sleep. Similar patterns were not found for the combination of allergy and dust mites or cat dander and high levels of the respective allergen.

COMMENT BY FRANK GRUSKAY, MD, FAAP, FAAI

Asthma is a leading cause of visits to the emergency room and hospitalization in children. Public health experts estimate that inner-city children are three times more likely to be hospitalized or to die from asthma than other children.1 Identifying plausible reasons for the prevalence and disproportionately high morbidity due to asthma among inner-city residents was the object of this study.2,3

Rosenstreich et al demonstrate that among these children, the highest morbidity rates caused by asthma (as measured by hospitalization rates and number of days wheezing) were associated with both a positive skin test to cockroach allergen and high levels of that allergen in the dust of the children’s bedrooms.

Treatment of allergic disease includes allergen avoidance, specific medication, and immunotherapy. A major effort to reduce the ubiquitous cockroach in inner-city houses by the use of safe insecticides and nontoxic traps should be an important part of management in these patients.

Immunotherapy with cockroach antigen, aimed at decreasing antigen-specific IgE as well as increasing blocking antibody, might be considered if asthma is poorly controlled by allergen avoidance and proper medication.

The Environmental Protection Agency (EPA) has focused its efforts on expensive new standards for improving the quality of outdoor air. These efforts cost more than $60 billion a year, and there is little evidence of improved health effects. Research on how to improve the quality of indoor air and its importance to patients suffering from asthma and other respiratory problems has not been well addressed. (Dr. Gruskay is Associate Clinical Professor of Pediatrics and Head of the Pediatric Immunology Clinic at Yale University School of Medicine.)

References

1. Call RS, et al. Risk factors for asthma in inner-city children. J Pediatr 1992;121:862.

2. Kang BC, et al. Atopic profile of inner-city asthma with a comparative analysis on the cockroach sensitive and ragweed sensitive subgroups. J Allergy Clin Immunol 1993;92:802.

3. Kang BC, et al. Study on cockroach antigen as a probable causative agent in bronchial asthma. J Allergy Clin Immunol 1976;58:357.