Influence of household pet ownership and filaggrin loss-of-function mutations on eczema prevalence in children: A birth cohort study

Kenji Toyokuni; Kiwako Yamamoto-Hanada; Limin Yang; Kouhei Hagino; Daisuke Harama; Marei Omori; Yasuaki Matsumoto; Daichi Suzuki; Kotaro Umezawa; Kazuma Takada; Mami Shimada; Seiko Hirai; Fumi Ishikawa; Sayaka Hamaguchi; Mayako Saito-Abe; Miori Sato; Yumiko Miyaji; Shigenori Kabashima; Tatsuki Fukuie; Emiko Noguchi; Kohta Suzuki; Yukihiro Ohya

doi:10.1016/j.alit.2024.01.003

Influence of household pet ownership and filaggrin loss-of-function mutations on eczema prevalence in children: A birth cohort study

Allergol Int. 2024 Jan 31:S1323-8930(24)00004-2. doi: 10.1016/j.alit.2024.01.003. Online ahead of print.

Authors

Kenji Toyokuni¹, Kiwako Yamamoto-Hanada², Limin Yang³, Kouhei Hagino³, Daisuke Harama³, Marei Omori³, Yasuaki Matsumoto³, Daichi Suzuki³, Kotaro Umezawa³, Kazuma Takada³, Mami Shimada³, Seiko Hirai³, Fumi Ishikawa¹, Sayaka Hamaguchi³, Mayako Saito-Abe³, Miori Sato¹, Yumiko Miyaji³, Shigenori Kabashima³, Tatsuki Fukuie³, Emiko Noguchi⁴, Kohta Suzuki⁵, Yukihiro Ohya³

Affiliations

¹ Allergy Center, National Center for Child Health and Development, Tokyo, Japan; Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine, Aichi, Japan.
² Allergy Center, National Center for Child Health and Development, Tokyo, Japan. Electronic address: yamamoto-k@ncchd.go.jp.
³ Allergy Center, National Center for Child Health and Development, Tokyo, Japan.
⁴ Department of Medical Genetics, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
⁵ Department of Health and Psychosocial Medicine, Aichi Medical University School of Medicine, Aichi, Japan.

PMID: 38302328
DOI: 10.1016/j.alit.2024.01.003

Abstract

Background: The association between pet exposure in infancy, early childhood eczema, and FLG mutations remains unclear.

Methods: This was a birth cohort study performed in Tokyo, Japan. The primary outcome was current eczema based on questionnaire responses collected repeatedly from birth to 5 years of age. Generalized estimating equations and generalized linear modeling were used to evaluate the association.

Results: Data from 1448 participants were used for analyses. Household dog ownership during gestation, early infancy, and 18 months of age significantly reduced the risk of current eczema. Household cat ownership also reduced the risk of current eczema, albeit without statistical significance. The combined evaluation of children from households with pets, be it cats, dogs or both, the risk of current eczema at 1-5 years of age was lower in those with household pet exposure ownership during gestation (RR = 0.59, 95 % CI 0.45-0.77) and at 6 months (RR = 0.49, 95 % CI 0.36-0.68). , Reduced risks of eczema were also observed at 2-5 (RR = 0.52, 95 % CI 0.37-0.73) and 3-5 years of age (RR = 0.50 95 % CI 0.35-0.74) when the respective household pet ownership were evaluated at 18 months and 3 years of age. These protective associations of reduced risk of eczema were only observed in children without FLG mutations.

Conclusions: Household dog and pet (dog, cat, or both) ownership was protective against early childhood eczema in a birth cohort dataset. This protective association was observed only in children without FLG mutations, which should be confirmed in studies with larger cohorts.

Keywords: Eczema; Filaggrin; Pet; Rhinitis; Wheezing.