Research: Smoking linked to allergies

There is "consistent and strong" evidence that children exposed to secondhand smoke in early infancy have a higher risk of developing allergies, according to researchers.

A group of Swedish scientists uncovered the evidence after studying 4,000 families and their children's allergies and environmental factors, such as smoking, that they had been exposed to before and after birth.

Their findings, published in the journal Thorax, revealed that children exposed to secondhand smoke had double the risk of being allergic to inhaled allergens, such as pet dander (animal hair and dead skin), compared to those who had not been exposed.

Children who breathed in secondhand smoke were also 50 per cent more likely to be allergic to foodstuffs.

"Our data indicate that [tobacco smoke] exposure in early infancy increases the risk of sensitisation to indoor inhalant and food allergens," the researchers report.

"The effects were consistent and strong."

The researchers add that their findings "may be of great clinical relevance" as sensitisation for allergies is important for incident asthma among children and adults.