Leonard B. Bacharier, MD

Exposure to indoor allergens contributes significantly to asthma morbidity, with children raised in inner-city areas particularly affected by such exposures. Most inner-city homes have evidence of mouse infestation,1 with a linear dose-response relationship between mouse allergen exposure and asthma morbidity among mouse-sensitized children and adolescents.2 Furthermore, a threshold exposure level of greater than 0.5 μg of the major mouse allergen (Mus m1) per gram of house dust has been identified as clinically relevant. Preschool children with asthma living in inner-city Baltimore, Maryland, who were sensitized to mouse allergen and exposed to greater than 0.5 μg/g of Mus m1 experienced 50% more symptom days, 80% more days of β-agonist use, and increased risks of emergency department visits and hospitalizations compared with children with lower levels of exposure.

JAMA