Wildfire smoke can trigger a host of respiratory and cardiovascular symptoms, ranging from runny nose and cough to a potentially life-threatening heart attack or stroke. A new study suggests that the dangers posed by wildfire smoke may also extend to the largest organ in the human body, and our first line of defense against outside threat: the skin.
During the two weeks in November 2018 when wildfire smoke from the Camp Fire choked the San Francisco Bay Area, health clinics in San Francisco saw an uptick in the number of patients visiting with concerns of eczema, also known as atopic dermatitis, and general itch, compared to the same time of the year in 2015 and 2016, the study found.
The findings suggest that even short-term exposure to hazardous air quality from wildfire smoke can be damaging to skin health. The report, carried out by physician researchers at the UC San Francisco, in collaboration with researchers at the UC Berkeley, appears on April 21 in the journal JAMA Dermatology.
“Existing research on air pollution and health outcomes has focused primarily on cardiac and respiratory health outcomes, and understandably so. But there is a gap in the research connecting air pollution and skin health,” said study lead author Raj Fadadu, a student in the UC Berkeley-UCSF Joint Medical Program. “Skin is the largest organ of the human body, and it's in constant interaction with the external environment. So, it makes sense that changes in the external environment, such as increases or decreases in air pollution, could affect our skin health.”
Air Pollutants Can Slip Through Skin Barriers
Air pollution from wildfires, which consists of fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs), and gases, can impact both normal and eczema-prone skin in a variety of ways. These pollutants often contain chemical compounds that act like keys, allowing them to slip past the skin’s outer barrier and penetrate into cells, where they can disrupt gene transcription, trigger oxidative stress or cause inflammation.
Eczema, or atopic dermatitis, is a chronic condition which affects the skin’s ability to serve as an effective barrier against environmental factors. Because the skin’s barrier has been compromised, people with this condition are prone to flare-ups of red, itchy skin in response to irritants, and may be even more prone to harm from air pollution.
“Skin is a very excellent physical barrier that separates us and protects us from the environment,” said study senior author Maria Wei, MD, PhD, a dermatologist and melanoma specialist at UCSF. “However, there are certain skin disorders, such as atopic dermatitis, in which the barrier is not fully functional. It's not normal even when you don't have a rash. So, it would make sense that when exposed to significant air pollution, people with this condition might see an effect on the skin.”