SOCIOECONOMIC-STATUS AND RACE AS RISK-FACTORS FOR COCKROACH ALLERGEN EXPOSURE AND SENSITIZATION IN CHILDREN WITH ASTHMA

Background: The domestic cockroach has been identified as an important source of indoor aeroallergens worldwide in both temperate and tropic al climates. Because cockroach populations are highest in crowded urba n areas, some have suggested that the increased asthma morbidity and m ortality rates in inner cities could be related in part to cockroach a llergen exposure. We have examined cockroach allergen exposure in the homes of children with asthma in both urban and suburban locations and have related the rates of exposure and sensitization to socioeconomic , racial, and demographic factors. Objective: The study was designed t o determine the independent contribution of race, socioeconomic status , and place of residence to the risk of cockroach allergen exposure an d sensitization in children with asthma. Methods: Eighty-seven childre n with moderate to severe allergic asthma, aged 5 to 17 years, partici pating in a prospective trial of immunotherapy, were evaluated. Extrac ted dust samples from three home locations were analyzed by using two- site monoclonal immunoassays for major cockroach allergens (Bla g 1 an d Bla g 2). A puncture skin test with a mixed cockroach allergen extra ct was performed in 81 of the 87 subjects. Results: In the 87 homes ev aluated 26% of the bedroom dust samples had detectable levels of cockr oach allergen. In homes with detectable bedroom cockroach allergen lev els, mean Bla g 1 and Bla g 2 concentrations in urban and suburban hom es were similar. Over 80% of children with bedroom Bla g 1 or Bla g 2 of 1 U/gm or greater demonstrated skin sensitivity to cockroach allerg en. The rate of cockroach sensitization was directly related to the le vel of bedroom exposure. African-American race was the only factor tha t was independently associated with cockroach allergen exposure (p = 0 .05). Lower socioeconomic status, age greater than 11 years, cockroach exposure, and African-American race were all independently associated with cockroach allergen sensitization on the basis of stepwise multip le linear regression analysis. Conclusions: African-American race and low socioeconomic status were both independent, significant risk facto rs for cockroach allergen sensitization in children with atopic asthma . Cockroach allergen is detectable throughout the house, including the critical bedroom environment.