Cockroach allergy appears early in life in inner-city children with recurrent wheezing

Background: Cockroach allergy and exposure to high levels of this allergen are important in the increasing asthma-related health problems among young inner-city children. However, there are very little data regarding the prev alence of cockroach allergy in infants and young children with asthma. Objective: This retrospective study was designed to test the hypothesis tha t cockroach allergy appears early in life in young children with recurrent wheezing. Methods: We reviewed the medical records of all 196 children (ages 5 months to 16 years) evaluated between January 1995 and September 1997 at the Cook County Hospital Pediatric Allergy Clinic for recurrent wheezing. The patie nts were assigned into two age groups, less than 4 years old and 4 to 16 ye ars old. The percentages of IgE skin tests positive for common aeroallergen s were compared within and between the two age groups. All children in the younger age group were tested for cockroach and dust mites, cat, and dog wh en indicated by positive environmental history. All children in the older a ge group were tested for indoor and outdoor allergens. Results: Sixty-three children were younger than 4 years of age, and of thes e, 15 (23.8%) had cockroach allergen sensitivity, compared with only eight patients (12.7%) who were skin test positive to dust mite allergen (P = .01 ). The youngest patient with a positive reaction to cockroach allergen was 6 months old. Patients with a single allergen skin reactivity were consider ed as monosensitized. Nine children younger than 4 years of age (14.3%) wer e monosensitized only to cockroach allergen in contrast to three children ( 4.8%) who were monosensitized to house-dust mites (P < .05). Conclusions: Our data suggest that cockroach allergen sensitivity starts ea rly in life and may be the only sensitizing allergen in many young inner-ci ty children.