Rat Sensitization Among Inner-City Asthmatic Children

Study objective: Inner-city asthma is a growing problem, and concerns remain about the role of exposure to multiple indoor allergens. Because of the increasing problems of rat infestation in New York and other cities, we sought to determine the frequency of sensitization to rat among inner-city children with asthma living in homes infested with cockroaches, and whether rat sensitization is associated with increased symptoms. Design/Setting/Participants: As part of the Columbia Intervention to Reduce Indoor Allergens Study, 37 Latino and African-American children age 5–18 years with asthma and determined to have positive skin tests to cockroach were evaluated for the presence of sensitization to rat by skin test and anti-rat-IgE levels. Clinical course was assessed by questionnaire. Results: We found that 43% had positive skin tests to rat, and 43% had an elevated anti-rat-IgE level. Anti-rat-IgE levels correlated with anti-cockroach-IgE levels (r =. 37, p =. 02) and mouse-IgE levels (r =. 72, p =. 001). Only one study participant reported seeing rats at home and rat allergen was not detected in any of the apartments. Cough and wheeze were not more frequent among those children sensitized to rats. Conclusions: Sensitization to rat may be frequent in inner-city asthma, although there is no evidence in our cohort that it is associated with increased symptoms among asthmatic children living in cockroach infested homes.