STOCKHOLM — A recent study published in Frontiers in Allergy concluded there was no association between living with a cat and worsened asthma outcomes in children. The study focused on Swedish children diagnosed with asthma or an airway allergy over a short-term period.
Researchers initiated the study in 2023, monitoring a cohort of 30,277 Swedish children aged four to 17 who were born between 2006 and 2020. The cohort was tracked for 24 months until 2024, utilizing data from the Swedish National Patient Register, Prescribed Drug Register, and National Airway Register. Data revealed that 9.4% of the children in the study lived in households with at least one cat in 2023.
The study found that moderate-to-severe asthma, based on prescribed medications, was documented in 9.6% of children exposed to cats and 10.1% of children not exposed to cats. Asthma exacerbation occurred in 3.3% of children exposed to cats, compared to 3.5% of children not exposed to cats.
Among a subset of 1,428 children with available asthma control and lung spirometry data, 97 children lived with cats. Analysis of lung function measures showed no differences between children living with cats and those living without cats. Asthma outcomes did not vary based on the number of cats, the cat's sex, or the cat's age.
Dr. Resthie R Putri, a postdoctoral fellow at Karolinska Institutet, commented on the findings. "Here we show in a nationwide cohort of children in Sweden with asthma and allergies, that children living with a cat had similar asthma severity, exacerbation, asthma control, and lung function to children living without cats in the short term. We also did not see any differences in asthma outcomes related to the number of cats, the cat's sex, or the cat's age," Dr. Putri said.
Dr. Putri offered a possible explanation for the results. She said, "One possible explanation is that cat allergen exposure is very common, even outside the home. Children who do not have cats at home may still be exposed in shared environments such as schools or public transportation, which could explain why we didn't see a difference."
The study authors acknowledged certain limitations. They noted that because the National Cat Register is relatively new, some children living with cats may have been misclassified as unexposed. The research also lacked data identifying which specific allergens sensitized the children in the cohort.