Environmental exposures and family history of asthma.

Background: Asthma pathogenesis is a complex interaction of genetic, ethnic, environmental and social/life style risk factors.

Aim: The goal of this study was to identify associations, if any, in children with asthma, between environmental risk factors (exposure to second-hand tobacco smoke (STS), pet ownership, race and a family history of asthma.

Methods: After IRB approval, from June 2011 to December 2014, 823 children with asthma were enrolled in this prospective cross sectional study. At the initial visit, families completed a questionnaire with information on family history of asthma, having a pet at home and exposure to STS by parents at home. Chi square analyses were calculated, with alpha level of significance ≤0.05.

Results: History of asthma in parents, siblings or grandparents was reported by 575 (69.8%) patients including father (n = 154, 17.8%) and mother (n = 235, 26.5%). Children with family history of asthma (n = 575) were significantly more likely to have a pet at home and exposure to STS (n = 347, 60.3% and n = 198, 34.4%, respectively) compared to families without a history of asthma (n = 124, 50%, p = 0.006 and n = 44, 17.7%, p < 0.001, respectively). Similarly, asthmatic children with exposure to STS (n = 241) were significantly more likely to have a pet at home and a family history of asthma (n = 153, 63.5% and n = 197, 81.7%, respectively) compared to children with no STS exposure (n = 315, 55.5%, p = 0.034 and n = 371, 65.3%, p < 0.001 respectively).

Conclusions: Significantly more asthmatic children with immediate relatives with a history of asthma have a pet at home and experience STS exposure compared to children without relatives with a history of asthma, suggesting association between life style choices/environmental exposures and family history of asthma.