Air pollution from wildfires may harm the skin, worsening symptoms of eczema and itch, according to a new study.
Wildfire smoke is known to exacerbate heart and lung conditions, triggering a host of respiratory and cardiovascular symptoms, ranging from a runny nose and cough to a potentially life-threatening heart attack or stroke.
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, according to a new study.
“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,” says Raj Fadadu, a student in the University of California, Berkeley-University of California, San Francisco Joint Medical Program and lead author of the study in JAMA Dermatology.
“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.”
Eczema and wildfire pollutants
Air pollution from wildfires, which consists of fine particulate matter (PM2.5), polycyclic aromatic hydrocarbons (PAHs), and gases, can affect 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 is a chronic condition that 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,” says senior author Maria Wei, a dermatologist and melanoma specialist at the University of California, San Francisco.
“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.”
Earlier studies have found a link between atopic dermatitis and air pollution in cities with high background levels of air pollution from cars and industry. However, this is the first study to examine the impacts of a very short burst of extremely hazardous air from wildfires. Despite being located 175 miles away from the Camp Fire, San Francisco saw an approximately ninefold increase in baseline PM2.5 levels during the time of the blaze.
How to protect your skin
To conduct the study, the team examined data from more than 8,000 adult and child visits to dermatology clinics between October of 2015, 2016, and 2018 and each February of the year that followed. They found that, during the Camp Fire, clinic visits for atopic dermatitis and general itch increased significantly in both adult and pediatric patients.
“Fully 89% of the patients that had itch during the time of the Camp Fire did not have a known diagnosis of atopic dermatitis, suggesting that folks with normal skin also experienced irritation and/or absorption of toxins within a very short period of time,” Wei says.
While skin conditions like eczema and itch may not be as life-threatening as the respiratory and cardiovascular impacts of wildfire smoke, they can still severely affect people’s lives, the researchers say. The study also documents increased rates of prescribed medications, such as steroids, during times of high air pollution, suggesting that patients can experience severe symptoms.
People can protect their skin during wildfire season by staying indoors, wearing clothing that covers the skin if they do go outside, and using emollients, which can strengthen the skin’s barrier function. A new medication, Tapinarof, to treat eczema is now in clinical trials and could also be a useful tool during times of bad air.
“A lot of the conversations about the health implications of climate change and air pollution don’t focus on skin health, but it’s important to recognize that skin conditions do affect people’s quality of life, their social interactions, and how they feel psychologically,” Fadadu says.
“I hope that these health impacts can be more integrated into policies and discussions about the wide-ranging health effects of climate change and air pollution.”
Additional coauthors are from the California Department of Public Health; the University of California, San Francisco; and the University of California, Berkeley. The UCSF Summer Explore Fellowship, the Alameda-Contra Costa Medical Association Summer Fellowship, and the UC Berkeley-UCSF Joint Medical Program Thesis Grant funded the work.
Source: UC Berkeley