The Effect of Dog Allergen Exposure on Asthma Morbidity Among Inner-City Children With Asthma

To determine the effect of dog allergen exposure on asthma morbidity among inner-city children with asthma.

This is a longitudinal observational cohort study of inner-city children in Baltimore age 5–12 years with a physician diagnosis of asthma. This study included 162 children, mostly African American, who were recruited from January 2009 to February 2015 and followed for 9 months. Majority (65.4%) had persistent asthma.

Patients were assessed at baseline, 3, 6, and 9 months. At each visit, asthma diaries, FeNO concentration, and home environment including presence and concentration of dog allergen (Can f 1 in house dust) were assessed. Allergic sensitization was determined at baseline through percutaneous skin prick testing or in vitro IgE testing.

Of the 162 children, 36% of children owned dogs and 27.2% were sensitized to dog. Dog allergen was identified in 88.9% of homes. Dog allergen exposure, regardless of sensitization status, was associated with patient-reported increased breathing difficulty, use of rescue inhaler, and activity limitations from asthma symptoms without significant change in acute care visits or FeNO. The independent effect of dog presence did not have significant changes on asthma morbidity.

Among inner-city children, dog allergen exposure is an independent risk factor for asthma morbidity.

This study highlights that dog allergen, similar to cat, can be present in homes that do not own a dog, causing significant effects on asthma control. Interestingly, it appears that sensitization status is independent of changes in asthma morbidity inferring that either IgE testing is missing a significant number of sensitized individuals or there are other effects that dog allergen has directly on the airway.