Acute exposure to thirdhand smoke may increase the risk of skin diseases such as contact dermatitis and psoriasis, according to a small study.

Thirdhand smoke (THS) comprises the residual pollutants from tobacco smoke that remain on surfaces and in dust after tobacco has been smoked.

It can remain on indoor surfaces indefinitely, causing potentially harmful exposure to both smokers and non-smokers.

Acute exposure of the skin to thirdhand smoke elevates biomarkers associated with the initiation of skin diseases. Biomarkers are natural substances that indicate a biological state, most commonly a disease.