Pet ownership affects childhood risk of asthma

A new study examining the risk factors for eczema in children finds that early sensitization to the family dog significantly reduces the risk of eczema in 4-year-olds, but in contrast, early exposure to the family cat increases the risk of eczema in cat-sensitized children. The study was published in the October online issue of the Journal of Pediatrics.

Researchers studied 636 children of atopic parents in the Cincinnati Childhood Allergy and Air Pollution Study population, a longitudinal birth cohort study on air pollution and allergy, who were followed from birth to age 4 and tested yearly with clinical evaluations, physical examinations, and skin prick tests (SPTs) for allergens. Parents completed annual in-person surveys regarding environmental exposures or eczema, reporting any scratching, redness, raised bumps, or dry skin or scaling for at least 6 of the last 12 months.

Results showed that of the 14% (n=90) of the 4-year-olds in the study who developed eczema, children who did not have a dog before 1 year of age and were dog SPT+ at 1, 2, or 3 years of age were 4 times as likely to have eczema as 4-year-olds who were SPT+ and who grew up with a family dog present. In contrast, children with family cats before 1 year of age who also were cat SPT+ were 13 times more likely to have eczema at 4 years of age than children who were SPT+ in cat-free households. Results also suggested that early dog ownership protects against the development of sensitivity to cats, independently of cat ownership or cat allergen levels.