Exposure during pregnancy, infancy, or childhood to dogs and other pets (but not cats) is significantly associated with a reduced risk of atopic dermatitis (AD) in childhood. Dogs may drool and cats may rule, but dogs reduce itchy skin disease! Go Sparky!(LOE = 2a)
Reference: Pelucchi C, Galeone C, Bach JF, La Vecchia C, Chatenoud L. Pet exposure and risk of atopic dermatitis at the pediatric age: A meta-analysis of birth cohort studies. J Allergy Clin Immunol 2013;132(3):616-622.
|Study Design: Meta-analysis (other)||Funding: Foundation|
|Setting: Various (meta-analysis)||Allocation: Unknown|
The “hygiene hypothesis” proposes that a reduced exposure to infectious agents in early life can affect the developing immune system and increase susceptibility to allergic and autoimmune disorders. These investigators searched MEDLINE and EMBASE and checked the reference lists of pertinent publications for studies reporting data on exposure to pets and AD in infants and children. Eligible studies included either cohort or case-control studies that evaluated exposure to dogs, cats, other pets, or pets overall during pregnancy, infancy, and/or childhood and the subsequent diagnosis of AD during infancy or childhood (12 years or younger). The authors do not report if decisions were performed independently by review team members, but discrepancies on individual study inclusion criteria were resolved by consensus agreement. Multiple analyses were performed to control for covariates, including family history of atopy, parental smoking, geographic area, parental education/income, and period of exposure. A total of 21 publications, all birth cohort studies, were identified, including 15 reporting data for dog exposure, 13 for cat exposure, and 11 to “pets.” Exposure to dogs compared with no exposure was significantly associated with a reduced risk of developing AD (relative risk [RR] = 0.72; 95% CI, 0.61-0.85). There was no significant association between exposure or no exposure to cats and the risk of AD. Exposure to “pets,” including dog or cat or other pet, was also significantly associated with a reduced risk of AD (RR = 0.75; 0.67-0.85). The authors reported minimal, if any, heterogeneity in their results and no evidence of significant publication bias.
David Slawson, MD
Vice Chair, Department of Family Medicine
University of Virginia