Babies who were exposed to secondhand smoke before they were born may face a higher risk of developing eczema later on in their childhood, according to researchers studying thousands of children and their exposure to environmental tobacco smoke.
With atopic dermatitis (or eczema), the skin can become so itchy, the scratching results in redness, cracking, and even fluid leaking, scaling, or crusting. This inflammatory condition affects up to 30 percent of people in the U.S. While asthma has previously been associated with secondhand smoke, the links to eczema have been unclear until now. As part of the Children's Health and Environmental Research (CHEER) survey, 3,639 children aged seven or eight were enrolled from 2005 to 2006. Their prenatal tobacco smoke exposure and eczema prevalence were measured with questionnaires, and researchers also collected blood samples. These children were followed up two years later.
Prenatal exposure as well as persistent exposure increased the risk of new atopic dermatitis diagnoses in children carrying particular variants of the genes that encode for TNF-alpha and TLR4, proteins that help regulate immune cells and activate the immune system. These variant forms (or polymorphisms) have previously been implicated in inflammatory conditions, Science News reports, like Crohn’s disease and rheumatoid arthritis. Harboring one of the gene variants and being (indirectly) exposed to tobacco smoke “may combine to worsen the development of atopic dermatitis,” University of Ulsan’s Soo-Jong Hong said at the American Academy of Allergy, Asthma & Immunology meeting last month, according to Science News.
The findings were published in the Journal of Allergy and Clinical Immunology in February.