No kidding

babies playing with cats are vulnerable to kitty-induced allergies and asthma later on, researchers in Sweden report. Their findings add to a body of conflicting evidence on whether being raised with a cat sensitises young children to the animals.

While the majority of research in this area has found early exposure to cats to be an allergy risk, some recent studies have suggested the other way round, that exposure helps infants develop a tolerance to cat allergens, thereby protecting them from allergies and asthma.

As per the journal, Allergy, in a study of 181 asthmatic children aged one to four, investigators found that those who lived with a cat during their first two years of life were more likely than other children to have developed a cat allergy by age four.

The primary offender is a protein found in the saliva and skin of all cats. Some of this protein is transferred to the hair as the cat grooms itself and hair floating in the air can irritate the respiratory tract of individuals with asthma and other airway diseases.

Asthma attacks are typically triggered by an allergic reaction to an environmental irritant such as pet dander, dust mites or cigarette smoke. The research group was led by Erik Melen of the Karolinska Hospital in Stockholm.

Besides the risk from early exposure to cats, Melen's team also found that children's risk of developing cat allergies was higher in homes harboring greater amounts of allergen-containing dust. Also, the combination of high cat allergen levels and parental smoking was linked to more severe asthma symptoms.

Experts have even recommended that families with a history of allergy and asthma keep cats out of the home for at least the first two years of a child's life.

"Our data clearly indicate that wheezy children should not live in homes where pets are kept," Melen and colleagues conclude. "Furthermore, they should preferably not have lived in such a home during their first few years, particularly not if the pet was a cat and a parent a smoker."