Mouse allergen skin sensitization in asthmatic children of suburban, rural, and inner-city populations.

Mouse allergen (MA) exposure is a well-known risk factor for allergic sensitization and is implicated in the pathogenesis of pediatric asthma. Although previous studies report high prevalence of MA sensitization in inner-city asthmatic children, no data exist on its comparison with either suburban or rural children with asthma. We did a retrospective cohort study by chart review of all children (≤18 years of age) who underwent allergy testing during a 6-month period in a tertiary care referral center. Patients were divided geographically into suburban, rural, and inner-city groups based on their zip codes. MA was tested using the standard allergy test panel by skin prick/puncture. Positive skin test reactivity was defined as wheal diameter ≥3 mm and erythema ≥5 mm. A total of 989 patients underwent allergy testing and 349 children were tested for MA with the overall positivity rate of 18.6% (65/349). In children with asthma (mean age, 12.8 years; SD ± 3.19) who had MA testing (n = 166), the rate of positive skin test reactivity was 18% (n = 30). Inner-city asthmatic children had significantly greater MA sensitization compared with either suburban or rural children. MA sensitization is highly prevalent among children with asthma, especially in inner-city populations but also among suburban and rural children. Although most allergists do not routinely test for MA sensitization during the initial evaluation, it may be useful to include it in the allergy testing for children with asthma.