Studies have found that exposure to mice is highly prevalent among children with asthma living in urban areas.
To examine the relationship between exposure to mice and wheeze in the first year of life.
We conducted an ongoing prospective birth cohort study of 498 children with a history of allergy or asthma in at least 1 parent living in metropolitan Boston (the Home Allergens and Asthma Study).
In a multivariate analysis, infants whose parents reported exposure to mice in the household had nearly twice the odds of developing any wheeze in the first year of life as children without exposure (odds ratio [OR], 1.83; 95% confidence interval [CI], 1.14–2.95; P = .01). Other variables associated with wheeze in the first year of life included low birth weight (OR, 1.77; 95% CI, 1.06–2.95; P = .03), having at least 1 lower respiratory tract illness (OR, 5.59; 95% CI, 3.46–9.04; P < .001), exposure to high levels of endotoxin at age 2 to 3 months (fourth quartile compared with first quartile: OR, 2.32; 95% CI, 1.19–4.54; P = .01), and exposure to cockroach allergen of 0.05 U/g of dust or more at age 2 to 3 months (OR, 1.83; 95% CI, 1.09–3.08; P = .02).
Among children with a parental history of asthma or allergies, exposure to mice is associated with wheeze in the first year of life, independent of other factors.