Risk factors for acute wheezing in infants and children: viruses, passive smoke, and IgE antibodies to inhalant allergens

Infants and children younger than two years of age who are routinely exposed to passive smoke are at greater risk for wheezing and viral infection. Researchers assessed the prevalence of viral infection, passive smoke exposure and immunoglobulin E (IgE) measurements in infants and children under two years. These children had a high rate of viral infection and a low rate of IgE antibody to inhalant allergens. When exposed to passive smoke, these children registered elevated levels of salivary cotinine that suggested considerable exposure. Beyond two years of age, sensitization to inhaled allergens became ever more important, and viruses continued to be a major risk factor. Odds ratios for wheezing were significant for virus and cotinine in children under the age of two. Young patients should have reduced tobacco smoke exposure at home and be sensitized to inhaled allergens and avoid allergens to prevent wheezing.
Objective. To examine the prevalence of viral infection, passive smoke exposure, and IgE antibody to inhaled allergens in infants and children treated for acute wheezing. Design. Case-control study of actively wheezing children who were compared with children without respiratory tract symptoms. Setting. University of Virginia Pediatric Emergency Room. Patients. Convenience sample of 99 wheezing patients (2 months to 16 years of age) and 57 control patients (6 months to 16 years of age). Measurements and results. Serum IgE antibody to inhalant allergens, measured by radioallergosorbent test (RAST), was uncommon in wheezing and control patients under age 2. After 2 years of age, the percentage of Rast-positive patients increased markedly and was significantly higher in wheezing patients than controls after age 4 (72%, n = 54, and 30%, n = 40, respectively, P age, particularly after age 2 years.