Smoking while pregnant or around an infant has long been linked to development of asthma and allergies in young children. Now, researchers have found that the risk may persist into the teen years.

The study, which followed nearly 4,000 children in Sweden for 16 years, underscores the dangers of parental smoking, experts say.

“Exposure to second-hand smoke during pregnancy or infancy increases a child’s risk of developing allergic disease even up to adolescence,” said study researcher Jesse Thacher, a doctoral student at the Karolinska Institute in Stockholm.

Fetal exposure to cigarette smoking was linked with an overall 45 percent higher risk of getting asthma up until age 16, Thacher found.

For infants exposed to a parent’s smoking, the risks of developing asthma and allergic rhinitis (stuffy or runny nose) in childhood or adolescence were 23 and 18 percent greater, respectively. The risk for eczema (inflamed, irritated skin) was 26 percent greater.