A Randomized Efficacy Trial of the Clinical Effects of Cockroach Allergen Reduction in Inner City Asthmatic Children

Abstract

Although extermination and cleaning reduces household cockroach allergen Bla g 1, the effect of allergen reduction on asthma symptoms in sensitized patients is not known. Asthmatic children with a positive cockroach (CR) skin test living in a CR infested inner city homes were included in this 6 month randomized, controlled trial. Treatment group homes were treated twice with hydromethylnon gel, then cleaned by professional cleaners, control homes were treated at 6 months. Bla g 1 was measured in settled dust before and at 2,4, and 6 months. Children were monitored at baseline, 2, 4, 6 months with symptom questionnaires, FEV1 and methacholine challenge. The 78 children were male (52%), African American (96%), with mean age 10.5 years. Over half (68%) reported daytime symptoms, 57% reported night wakenings and 52% activity interference; 17% reported an ED visit within last 3 months; median FEV1 was normal. Bla g 1 in kitchen dust was 114 U/gm in control homes, 34 in treatment homes. At 6 months Bla g 1 decreased 59% in treatment homes, 39% in control homes (difference p < 0.03, GEE). Symptoms with activity decreased 41% in treated children, 11% in control children (difference p < 0.17, GEE). Other symptoms changed less. Cockroach allergen was reduced in inner city homes after extermination and cleaning. However, symptoms in sensitized asthmatic children living in these homes did not decrease significantly.