PURPOSE OF THE STUDY.
Environmental tobacco smoke (ETS) in children is associated with respiratory infections, impaired lung function, and increased risk of asthma. The association between ETS and total and specific immunoglobulin (Ig)E has not been extensively investigated.
The meta-analysis included studies with participants aged 0 to 18 years from nonselected, random populations reporting the effects of postnatal ETS exposure on total IgE (tIgE) concentrations or allergen-specific IgE (sIgE) or skin prick test (SPT) results to any common food or inhalant allergen.
Cochrane and Medline databases were systematically searched by 3 researchers using prespecified search terms, and MOOSE (Meta-analysis Of Observational Studies in Epidemiology) criteria were applied for analysis and reporting.
Eight studies on the influence of ETS on tIgE concentration (2603 patients), 6 studies on ETS and sIgE (9230 participants), and 11 studies on ETS and SPT (14 150 patients) met inclusion criteria. ETS was shown to raise tIgE concentration by 27.7 IU/mL (95% confidence interval [CI] 7.8–47.7) and to increase the risk of atopic sensitization as assessed by detectable sIgE (odds ratio = 1.12, 95% CI 1.00–1.25) and positive SPT (odds ratio = 1.15; 95% CI 1.04–1.28).
The study results support an association between ETS exposure in early childhood and an increased risk of allergic sensitization.
These are modest increases in the risk for allergic sensitization, and not all of the sensitization represents clinical disease. However, given that the Environmental Protection Agency estimates that 11% of all US children under age 7 years are exposed to ETS in their homes on a regular basis, this represents a large number of children. Thus, when trying to convince parents to quit smoking, or at least not smoke around their children, we can tell them that smoke exposure increases their children’s risk not only of respiratory infections, impaired lung function, and asthma but of allergies as well.
- Copyright © 2015 by the American Academy of Pediatrics