A new study suggests that couples expecting their first child should reconsider owning a cat if they have a family history of eczema.
Eczema, which causes itchy, flaky skin and affects up to one in five children, tends to run in families.
Newborn babies with a defective inherited gene are more likely to develop the painful skin condition if they are exposed to cats, scientists have discovered.
Researchers have uncovered a link between the disease and a specific inherited gene which normally works by producing a protein which protects the skin.
However, in around one in ten children the gene does not work properly, leaving them more prone to allergy.
Researchers compared a high-risk group of 379 Danish infants who had the defective gene with a group of 593 babies from the general population in Manchester.
In both groups, they found that children with the defective gene were twice as likely to develop eczema during their first year of life as those without the genetic faults.
However, the study showed that having a cat further increased the risk of developing the disease.
The scientists said that they were unsure how exposure to cats was linked to the development of eczema.
They have ruled out the normal way in which allergies affect the body, because the children did not produce cat-specific antibodies in their blood.