Chemicals that pollute breathable air from vehicle exhaust pipes and are also used in numerous common products may be linked to a high rate of atopic dermatitis, more commonly known as eczema, in infancy, according to a recent study by the National Institutes of Health.
"We have solid data establishing that pollutants are very likely behind increasing cases of atopic dermatitis," said Dr. Ian Myles, chief of the Epithelial Research Unit in the National Institute of Allergy and Infectious Diseases Laboratory of Clinical Immunology and Microbiology, via NBC News.
Eczema is an itchy, inflammatory skin condition that is reported to affect 31.6 million Americans, typically beginning in the patient's first year of life and peaking in early childhood, according to the National Eczema Association via NBC News. The condition can be triggered by several allergens, including pets, perfumes, dyes and food.
Genetics have long been believed to play a vital role in eczema, but the rapid rate of increased cases -- which is estimated to be two to three times greater in industrialized countries since the 1970s -- has puzzled experts. Myles and his research team discovered that "hot spots" where the disease was most common had toxins in the surrounding environment and similar chemicals called diisocyanates and isocyanates were found to be most prevalent.
Diiocyanates are commonly used in the manufacturing process of polyurethane products, which includes adhesives, flexible foams, carpeting and fabrics that stretch or are weather-resistant. The Agency for Toxic Substances and Disease Registry, which is part of the U.S. Centers for Disease Control and Prevention, has stated that chemicals are unlikely to be toxic in polyurethane products if the items have been cured appropriately by the manufacturer, which has led to researchers focusing on exhaust fumes' role in the rapid rate of cases.
Catalytic converters, which became mandatory on all vehicles in the U.S. in 1975, coinciding with the initial spike in eczema cases, intend to limit harmful chemicals in gasoline, but produce isocyanates as a byproduct, which experts believe plays a role in the increased cases.
"I think these authors are spot on in recognizing that the incidence of allergic conditions is increasing concurrently with how different pollutants are increasing in our environment," said Dr. Jessica Hui, a pediatric allergist and immunologist at National Jewish Health in Denver, via NBC News."We're finally understanding more about why people are getting eczema."