From the Guidelines
Having pets at home does not require special avoidance in infants and preschool children to reduce the risk of developing allergy or asthma, as the current evidence suggests no significant benefit in avoidance. According to the allergic rhinitis and its impact on asthma (aria) guidelines: 2010 revision 1, the recommendation is to not avoid exposure to pets at home in infants and preschool children, placing a relatively high value on possible psychosocial downsides of not having a pet. Key points to consider include:
- The recommendation is based on low-quality evidence, suggesting that the relationship between pet exposure and allergy/asthma development is not fully understood.
- Clinicians and patients may choose alternative actions based on individual circumstances, such as other sensitized family members.
- The "hygiene hypothesis" suggests that early exposure to certain microbes, including those from pets, may help the immune system develop properly, potentially reducing the risk of allergies and asthma.
- However, if a child already has established allergies to pets, continued exposure may worsen symptoms, and good household cleaning practices are essential to manage overall allergen levels. In real-life clinical practice, the decision to have pets at home should be made on a case-by-case basis, considering the potential benefits and risks for each family, as suggested by the aria guidelines 1.
From the Research
Pet Exposure and Allergy Risk in Children
- Studies have investigated the relationship between pet exposure and the risk of allergies in children, with some suggesting that pet exposure may reduce the risk of allergic sensitization and disease 2.
- A study published in 2012 found that exposure to cats or dogs at birth was associated with a moderate reduction in the risk of wheeze and hay fever after 7 years of age 3.
- Another study published in 2009 found that children who owned both a cat and a dog were less likely to be atopic at age 13 years, and that having both pets in adulthood was associated with a lower risk of new atopy by age 32 years 4.
- A 2019 study found that dog- or cat-keeping during the first year of life reduced the risk of sensitization to dog or cat allergens, and that cat-keeping during or after the first year of life reduced the risk of cat allergy and hay fever 5.
Contrasting Findings
- However, not all studies have found a protective effect of pet exposure on allergy risk. A 2008 study found that keeping dogs or cats at the time of the survey or during the child's first years was associated with an increased risk of symptoms in airways, nose, and skin among children aged 2-7 years 6.
- The evidence suggests that the relationship between pet exposure and allergy risk in children is complex and may depend on various factors, including the type of pet, the timing and duration of exposure, and individual susceptibility 2, 3, 4, 5.
Mechanisms and Implications
- The mechanisms by which pet exposure may influence allergy risk are not fully understood, but may involve changes in microbial exposures and the development of the immune system 2.
- Further research is needed to clarify the relationship between pet exposure and allergy risk in children and to inform strategies for preventing allergic diseases 2, 3, 4, 5.