Environmental exposures and family history of asthma

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

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.

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.

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).

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.