Smoke and the skin

By Emily Margosian, Senior Editor, June 1, 2025

From wildfires to cigarettes, smoke drifts through every corner of life.

Nearly 90% of the world’s population lives with unhealthy air caused by smoke, according to Massachusetts dermatologist Christine Kannler, MD, FAAD, with the potential for immediate and long-term cutaneous effects. “These chemicals are known to alter the redox status, which means there’s an increase in oxidative stress. This produces a compound called 4-hydroxy-2-nonenal (HNE) which is highly reactive and can overlap with skin inflammatory conditions such as urticaria, psoriasis, and eczema,” she explained. “When thinking about smoke, the skin is our largest organ and the main target of air pollution beyond the lungs. Air pollution can include everything from cigarette smoke to fossil fuel burning, manufacturing, motor vehicles, agricultural sources, and — increasingly — wildfires.”

As wildfire season in the United States has become longer, more intense, and more destructive in recent decades, exposure to smoke and its potential effects on the skin are of growing concern to physicians, patients, and the public.

Short-term impact of smoke exposure on the skin

As wildfires become more prevalent and widespread, researchers have sought to better understand the impact of exposure to the smoke they produce.

A study following the 2018 Camp Fire in California found short-term wildfire smoke exposure was significantly associated with increased rates of weekly pediatric and adult appointments for atopic dermatitis and itch (doi: 10.1001/jamadermatol.2021.0179). “We found that during the second week of the wildfire, dermatology visits to the University of California, San Francisco increased above the usual level of visits for that time of year in the absence of fires, and the number of visits stayed up for at least four weeks, even when we adjusted for other factors that might affect eczema, such as temperature and humidity,” said study author Maria Wei, MD, PhD, FAAD, professor of dermatology at University of California, San Francisco.

According to Dr. Wei, the number of clinic visits to dermatology for itch also went up significantly, “Interestingly, most of those patients did not have a diagnosis of eczema,” she explained. “Our data, while not direct evidence of cause and effect, suggest that exposure to wildfire smoke causes eczema to flare, and causes itching even in those without a diagnosis of eczema.”

Short-term exposure to wildfire smoke has also been associated with increased acne clinic visits among adults (doi: 10.1016/j.jaad.2024.07.550) and psoriasis visits among adults (doi: 10.1001/jamanetworkopen.2022.51553). “Likely many, if not all inflammatory skin diseases, will be affected in a negative way by exposure to wildfire smoke and air pollution in general,” said Dr. Wei.

“We have all these amazing therapeutics that are revolutionizing our care for many conditions, but if our natural environment makes them ineffective, that’s a problem.”

According to Markus Boos, MD, PhD, FAAD, pediatric dermatologist at Seattle Children’s Hospital and associate professor of pediatrics at the University of Washington School of Medicine, there is also evidence that wildfire smoke may flare conditions such as pemphigus, lupus, and vitiligo. “Smoke exposure causes inflammation in the skin, and in response, we’re activating inflammatory pathways that lead to these dermatoses,” he explained. “We know that when particulate matter of fossil fuel combustion touches our skin, they trigger inflammatory pathways. The first is a transcription factor called the pregnane X receptor. The job of this is to remove foreign particles — also called xenobiotics — from the skin. In the process of doing that, it makes our skin drier and scalier. There’s a separate pathway that also gets activated. That’s the aryl hydrocarbon receptor pathway. Downstream of all these pathways is stimulation of the Th2 and the Th17 pathways. Those are the pathways that are involved in both atopic dermatitis and psoriasis. Mechanistically, we know this makes sense. We have evidence in mouse models that these pathways that lead to atopic dermatitis are upregulated when skin is exposed to the byproducts of fossil fuel combustion, whether that’s wildfire smoke, car exhaust, or other ways that we’re burning fossil fuels. It’s important for all of us as dermatologists to keep in mind that the skin is not just this barrier that’s keeping smoke out. It’s responding to the environment that we’re existing in.”

In addition to establishing a link between smoke exposure and skin disease, research also suggests that flares of skin disease after exposure to wildfires may be more severe. “Eczema present at visits that took place during and after the Camp Fire was serious, as our data show that the number of prescriptions for systemic medications increased during and after short-term exposure to wildfire smoke,” said Dr. Wei.

Research also suggests that the severity of flares triggered by wildfires may disrupt the efficacy of otherwise effective treatment options (doi: 10.1016/j.jdin.2023.01.018). “There was a recent study on people whose atopic dermatitis was previously well-controlled on dupilumab and experienced breakthroughs during wildfire season,” said Dr. Boos. “I think that matters in the sense that we have all these amazing therapeutics that are revolutionizing our care for many conditions, but if our natural environment makes them ineffective, that’s a problem.”

Smoke and skin aging

Smoke from air pollution has also been linked to long-term effects on the skin, including hyperpigmentation, increased sensitivity, and premature aging.

“We do have evidence that when people are exposed to smoke, there is an increase in aging of the skin,” said Dr. Boos. “People who are chronically exposed to air pollution are more likely to get wrinkles, lentigines, and melasma. All these things we associate with the aging process as it relates to the skin are accelerated with chronic exposure to pollution.”

Occupational risk

Veterans

In addition to environmental exposures, occupations requiring prolonged subjection to smoke also have a higher risk of developing associated skin disease.

Among active-duty military and veterans, the impact of exposure to burn pit smoke is an issue that has recently come into focus. “In a military environment, you have to get rid of waste quickly,” explained Eugene Sanik, DO, FAOCD, a dermatologist at James A. Haley Veterans’ Hospital Dermatology Clinic in Tampa, Florida. “In these burn pits they were incinerating hundreds of tons of chemicals, medical waste, batteries, munitions, and plastics per day. These were also being ignited with benzene-based, jet fuel propellants which are well-known carcinogens.”

The PACT Act, passed in 2022, expanded VA health care and benefits for veterans exposed to burn pits, Agent Orange, and other toxic substances during their service. “If you served in the Gulf War or in a post-9/11 war, it is now presumed that you have had burn pit exposure. Under the PACT Act, if you have any of the presumptive conditions — about 10 cancers and 10 other illnesses — you don’t have to prove that it was due to burn pits, the VA automatically considers it service-connected. This hugely simplifies the process of getting disability benefits,” explained Dr. Sanik.

At his VA clinic, Dr. Sanik says he sees veterans ranging from 30 to 50 years of age presenting with skin conditions they believe are linked to smoke exposure during their service. “Often, they ask questions like, ‘Is my rash because of burn pits? Is it because of all the toxins created in these pits?’ It’s a tricky question because it’s challenging to quantify, but the answer is probably yes. I think the weight of the evidence strongly suggests that a lot of the chemicals found in burn pit smoke — dioxins, hydrocarbons, and fine matter particulates — are playing a role in the skin diseases that we treat in veterans every day. You see a lot of similarities in the private sector, particularly among firefighters or chemical plant workers who are exposed to very similar toxins.”

In addition to rashes and inflammatory disorders, veterans with burn pit exposure may also have an increased risk of skin cancer. “In our clinic alone, we diagnose about 150 melanomas per year and I would say at least a third of those are from folks under 50,” said Dr. Sanik. “A good chunk of them have had service in areas that are covered by the PACT Act. Sarcomas are rarer, but we also see dermatofibrosarcoma, liposarcomas, leiomyosarcoma, and angiosarcomas as well. If you’re a dermatologist and you see a veteran returning from deployment who reports rashes or cancers, it’s always a great idea to have them understand and use their benefits to get the care that they need. The VA is then also able to capture this data and record how many folks have service-connected disease, which helps further support other veterans facing the same conditions.”

Firefighters

Per the job description, firefighters have heavy occupational exposure to smoke. This puts them at elevated risk of cancer compared to non-firefighters, research suggests (doi: 10.1136/oemed-2013-101803). “The Nordic study did find an increased risk of melanoma compared to non-firefighters. What they also found is that melanoma in firefighters was happening at an increased rate — ages 30 to 50 — decades earlier than the average man who gets melanoma,” said Dr. Kannler. “The other data that we can use for firefighter skin melanoma incidence rates is the World Trade Center 14-year follow-up study. Among surviving firefighters who arrived on 9/11, there was a higher standardized incidence ratio of melanoma. They also found that the firefighters who were located on the rubble pile had a higher incidence of melanoma compared to the firefighters who were stationed streets away. So, there’s also a relationship between what’s burning and the closer you are to it and your melanoma risk.”

“Our firefighters are really exposed to this soup of pollution. How those chemicals interact with each other, and how another environmental exposure — such as UVA light — triggers them to change is particularly fascinating and really scary.”

The type of fire and the smoke it produces can also impact firefighters’ level of risk, depending on the materials burned. “When we think about wildfire smoke composition, it’s a mixture of gases, particulate matter, and volatile organic compounds (VOCs) formed from the burning of vegetation or organic matter,” explained Dr. Kannler. “The recent fires that we just had in the Palisades in California are what we would call an urban-wildland interface. You have all the natural contaminants that are present in wildfire but also must factor in toxic chemicals from the pyrolysis of plastic and other manufactured materials. Our firefighters are really exposed to this soup of pollution. How those chemicals interact with each other, and how another environmental exposure — such as UVA light — triggers them to change is particularly fascinating and really scary.”

How to protect the skin from smoke exposure

While there are no official guidelines or studies on the effectiveness of protective strategies, there are still proactive steps patients can take in the event of a wildfire or other significant exposure to smoke, dermatologists say.

Dr. Wei recommends staying indoors with the windows and doors closed during wildfire season and wearing long sleeves and pants when outside.

Patients may also want to consider a quick rinse at the end of each day followed by a moisturizer to help protect the skin barrier, suggests Dr. Boos. “During wildfire season, air quality indoors is impacted as well. For those who can afford it, having an air purifier in the home is also important. If a family can’t afford an air purifier, an alternative is getting a box fan and rigging it up with some cardboard in the window to blow air out of the home. There are different fixes that are a little bit more affordable, and there are YouTube videos available on how to make those fans.”

“I would recommend getting an air purifier because it does clean out particulate matter,” agreed Dr. Kannler. “The filter number that you want to look for is particulate matter (PM) 2.5. That refers to fine particles of air pollution with a diameter of 2.5 micrometers or less. That’s the size at which they can get into your blood or skin.”

After experiencing a particularly bad fire season, Dr. Boos says patient education regarding skin health has become more front of mind in recent years. “The week after a local wildfire was at its worst, I had my urgent care clinic with 12 slots available, and of those slots, 11 were for kids with atopic dermatitis flares. It made it immediate and real once it was something that I was seeing in my practice,” he recalled. “If you’re not paying attention, it’s easy to say, ‘I see atopic dermatitis all the time,’ and not make that connection, but it’s important for us as dermatologists to make that connection because we can give guidance on how to protect the skin when we know it’s going to be a bad smoke day.”

The increasing frequency and severity of extreme weather events continues to impact human health. “With increasing exposure to wildfire smoke, several common types of inflammatory skin disease appear to flare during and after exposure, including atopic dermatitis, psoriasis, and acne,” said Dr. Wei. As wildfire season continues to extend in length and severity, researchers suggest that dermatologists should prepare to treat more cases of skin diseases that can flare with increases in air pollution.

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