Questionnaire-based Study on the Relationship between Pet-keeping and Allergic Diseases in Young Children in Japan

It is still unclear how early exposure to pets is related to the risk of developing atopy-related diseases in children. There are few reports on this pet-allergy relationship in Japan although much controversial data have been reported in Europe and the USA. A questionnaire on pet-keeping and allergic diseases was distributed to parents of children 3-6 years of age who belonged to 4 kindergarten and 2 nursery schools in Gifu city and surrounding areas. A total of 1185 questionnaires were analyzed statistically. Bronchial asthma (11.6%), atopic dermatitis (16.5%), and allergic rhinitis (16.5%) were reported. Dogs, cats, hamsters, rabbits, and birds were kept by 21.6%, 5.5%, 10%, 1.5%, and 2.6% of all families, respectively. Indoor pets with fur resulted in a significantly higher prevalence of atopic dermatitis (OR = 1.82, 95% CI 1.26-2.63) using univariate analysis and also in multivariate logistic regression analysis. We also found a significantly higher prevalence of atopic dermatitis in subjects who started keeping dogs and/or cats indoors after 1 year of age, compared to subjects who kept neither dogs nor cats, using both univariate analysis (OR = 2.26, 95%CI 1.13-4.54) and multivariate logistic regression analysis (OR = 2.17, 95%CI 1.09-4.32). We found no evidence that pet-keeping protects people from developing various allergies. Conversely, indoor pets with fur have a slightly increased prevalence of atopic dermatitis.