A large study of Korean teenagers finds that being around cigarette smoke—either by actively smoking or passive exposure—is associated with having atopic dermatitis. And, the more one is around cigarette smoke, the stronger the link.
The authors, publishing in the journal PLoS ONE, acknowledged their findings might be controversial given previous conflicting results in this area. But the size of this study—more than 135,600 participants were interviewed—and the representativeness of the population are strengths, they said.
Results are based on data gathered from the Korean Youth Risk Behavioral Web-based Survey, conducted in 2011 and 2012. The researchers grouped the teens into 3 groups: those who smoked 20 day a month or more, those who smoked less than 20 days a month, and those who did not smoke. Similarly, they examined passive smoke exposure and identified 3 groups: those who typically had no exposure, those exposed 4 days a week or less, and those exposed 5 days a week or more.
Overall, 6.8% of the participants, or 10,020 teens, reported having atopic dermatitis in the previous 12 months. Active smoking was strongly associated with the condition; those who smoked at least 20 days a month had an adjusted odds ratio (AOR) of 1.18, compared with an AOR of 1.11 for those who smoked less than 20 days. Passive smoke exposure of at least 5 days a week brought an AOR of 1.12, compared with 1.08 for 1 to 4 days a week. The researchers also looked at whether e-cigarettes were linked with atopic dermatitis and found they were not.
What would explain the link between smoking and atopic dermatitis? The researchers go through several possible explanations, including the known link between smoking and inflammation.
“Strong correlations have been found between smoking and various inflammatory markers, such as the white blood cell count, fibrinogen level, plasma viscosity, and high-sensitivity C-reactive protein level,” they wrote. “The skin barrier function can be damaged by toxic substances produced by smoking, such as nicotine and carbon monoxide, which disturb the blood flow and oxygenation of the skin. These disturbances of the skin and associated subcutaneous structures allow allergens to permeate into the skin, which results in atopic dermatitis.”
In 2014, CDC issued new findings on the 50th anniversary of the landmark report, Smoking and Health, which exposed the connection between smoking and cancer; in the new report, CDC presented evidence that smoking causes or aggravates a number of conditions related to inflammatory response, including diabetes and rheumatoid arthritis. The report linked smoking to damage to the body’s immune response; atopic dermatitis is known to be connected to an overreaction of the immune system.
12(11):e0187453. doi: 10.1371/journal.pone.0187453.
Kim SY, Sim S, Choi HG. Atopic dermatitis is associated with active and passive cigarette smoking in adolescents [published online November 1, 2017]. PLoS ONE. 2017;