New Delhi: Having a pet dog at home during a baby’s early life might help prevent eczema, especially in children who are genetically more likely to develop the condition, a major new study suggests.

Researchers found that children with a certain DNA variation had a lower risk of developing eczema if they were exposed to a dog in their first year of life. The study, published in the journal Allergy, analysed data from nearly 300,000 people and offers fresh insight into how genes and environment interact in allergic diseases.

The research was led by scientists from the Universities of Edinburgh and Bristol, the London School of Hygiene & Tropical Medicine, and Helmholtz Munich, and involved teams from 14 countries including the UK, Germany, Denmark, the US, and Australia.

Researchers studied 24 known genetic risk factors for eczema and 18 early-life environmental exposures, such as pet ownership, smoking, breastfeeding, and antibiotic use.

An initial analysis of over 25,000 people suggested links between seven environmental factors and eczema risk genes. These included owning a dog, having older siblings, cat ownership, smoking, breastfeeding, antibiotic use, and washing habits.

When researchers looked at a much larger group of nearly 255,000 people, the strongest finding was the link between dog ownership and a reduced eczema risk in children carrying a specific genetic variation near the gene for interleukin-7 receptor (IL-7R), a protein involved in immune function and inflammation.

Lab tests confirmed that in skin cells with this gene variant, molecules linked to dogs that might normally trigger allergies instead helped reduce inflammation.

Dr Marie Standl, from Helmholtz Munich, said,"This study sheds light on why some children develop eczema in response to environmental exposures while others don't. Not every preventive measure works for everyone – and that's precisely why gene–environment studies are crucial. They help us move toward more personalized, effective prevention strategies."

Professor Sara Brown, from the University of Edinburgh's Institute of Genetics and Cancer, said, "The most difficult questions I'm asked by parents in clinic are about why their child has eczema, and how they can help. We know that genetic make-up affects a child's risk of developing eczema and previous studies have shown that owning a pet dog may be protective, but this is the first study to show how this may occur at a molecular level. More work is needed, but our findings mean we have a chance to intervene in the rise of allergic disease, to protect future generations."

The study also found a possible protective link in children with older siblings, supporting the idea that early exposure to a range of microbes, whether from pets or other children, may help build stronger immune responses. However, more research is needed to confirm this.

Experts caution that the study did not look at whether getting a dog could help treat existing eczema. In some children, it might even make symptoms worse.

The study was limited to white European populations. The researchers say more diverse studies are needed to better understand how genes and environment interact in different ethnic groups.

Rishika Verma
Rishika Verma

Rishika Verma is a graduate from Delhi University. She joined Medical Dialogues in 2023. Her interest lies in reporting health news, hospital updates, health updates, medical case studies, and advancements in healthcare, etc.