Early Life Domestic Pet Ownership, and the Risk of Pet Sensitization and Atopic Dermatitis in Preschool Children: A Prospective Birth Cohort in Shanghai

Abstract

Background: Although domestic pet ownership is on the rise, the impact of early life pet ownership on children's pet sensitization and atopic dermatitis (AD) remains controversial. Methods: Shanghai Allergy Cohort is an ongoing prospective study followed up to the age of 5 years. Pregnant mothers were recruited and their offspring were followed up every year by a group of pediatricians. Information on furred pet ownership was collected by the questionnaire. AD was diagnosed by dermatologists according to disease history and Williams criteria at 5 years ± 1 months. Skin prick test (SPT) was performed to determine sensitization to specific allergens. Multiple logistic regression models were used to evaluate the associations between pet ownership and AD, dog/cat sensitization. Results: In the 538 children at preschool age, 112 (20.82%) were diagnosed with AD. Dermatophagoides pteronyssinus and Dermatophagoides farina were the most common allergens, and almost 10% of children were positive to dog and cat. The percentage of positive SPT reactors at 5-year old was 65.28% in the group of children with AD, higher than that in non-AD group (44.57%). Domestic pet ownership at both infant and preschool period was positively associated with an increased risk of sensitization to dog (OR adjusted = 2.85 [95% CI: 1.08-7.50 for infant exposure], OR adjusted = 2.73 [95% CI: 1.33-5.61] for preschool exposure), and interestingly, pet ownership at infant period negatively associated with higher risk of AD at 5-year old (OR adjusted = 0.33 [95% CI: 0.12-0.88]). Conclusion: This is the first prospective birth cohort study in Shanghai that found half of preschool children had positive allergen sensitization even in the non-AD children. Although early life exposure to dog may increase the risk of dog sensitization, it significantly decreased the risk of AD. The underlying mechanisms warrant further investigations.

Associations of early-life pet ownership with asthma and allergic sensitization: A meta-analysis of more than 77,000 children from the EU Child Cohort Network

“…We found no strong evidence for an association between cat or dog ownership and allergic sensitization to the respective allergen, suggesting that ownership is unlikely to be the main determinant of cat-and dog-specific allergic sensitization; instead, other factors such as genetic susceptibility are likely decisive. Other cohort studies examining associations of pet ownership with allergic sensitization to associated allergens have been conflicting, with some reporting a positive association 72,73 and others reporting either no 20,[73][74][75][76][77][78] or an inverse association. 20,23,[78][79][80] These inconsistencies could be related to differences in the timing of assessment of allergic sensitization, because trajectories of pet-specific allergic sensitization have been observed to differ in pet owners versus in non-pet owners.…”

Colliding and interacting microbiomes and microbial communities ‐ consequences for human health

“…Misic and colleagues (2015) also reported microbiota sharing between cohabiting humans and pets (cats and dogs). Exposure to dogs in early life has been associated with decreased risk of atopic dermatitis (Li et al ., 2020), and exposure to a dog before and during pregnancy has been shown to decrease the risk of food allergy in the first year of life, which the authors suggest may be due to the beneficial effects of the dog's microbes (Smejda et al ., 2020). The beneficial effect arising from dogs in the home may be a consequence of immune modulation following exposure to a more diverse microbiota.…”

Revisiting the MMTV Zoonotic Hypothesis to Account for Geographic Variation in Breast Cancer Incidence

“…It is worth noting that the incidence of murine typhus, transmitted to humans from mice by fleas infected with Ricketsia typhi , is highest in the proximity of major international seaports in Taiwan [ 47 ]. While pet dog ownership in Taiwan and China has become very popular in recent years [ 48 ], and while an initial retrospective study suggested that dog owners were at increased risk of developing breast cancer [ 49 ], this observation has not been confirmed in a larger prospective study [ 50 ]. As we suggested previously, direct fecal-oral transmission from mice to humans seems more likely [ 16 ].…”