Asthma is very common among children living in inner-city areas, and it has been known for a while that allergens from cockroaches in their homes contribute to the disease. Two articles published in todays Journal of Allergy and Clinical Immunology address the question of whether mice, which often lead to allergies in people who are exposed to them at work, also play a role in asthma.
Robert A. Wood from Johns Hopkins University and his colleagues analyzed dust samples from 608 homes of children with asthma in inner-city areas of New York, Washington, D.C., Baltimore, Chicago, Cleveland, Detroit and St. Louis. Ninety-five percent of them contained mouse allergen in at least one room, and the highest levels appeared in the kitchen, suggesting that mice had visited at some point.
Then the scientists tested 499 asthmatic children living in these homes for a variety of allergies, using a puncture skin test. About one fifth of them turned out to be sensitive to mice. Children who were prone to allergies in general were more often allergic to mice, especially if they were also exposed to high levels of mouse allergen at home. The children who were sensitive to mice, however, did not have more severe asthma than the children who were not. Thus, although mouse allergen is extremely widespread in inner-city homes, it does not seem to play the same role in asthma as cockroaches do.