One surprising effect of wildfires: Itchy, irritated skin
Are you finding yourself with itchy, irritated skin that you can’t stop scratching? Or have you wondered why your child’s eczema is suddenly worse and so hard to control? Mounting evidence suggests that wildfires, which are increasing in intensity and frequency, contribute to skin problems, including eczema flares.
What is eczema?
Eczema is a common chronic skin condition that affects about one in 10 people in the US. Its hallmarks are inflamed and dry, itchy patches of skin.
Atopic dermatitis is the most common type of eczema. It can run in families, often beginning in childhood. Typically, in the northern hemisphere, it grows worse during the winter season when the weather is cold and drying. Now some experts are seeing that pattern change. At Massachusetts General Hospital, for example, one dermatologist noted an unusual spike last summer in patients with flare-ups of eczema.
Why is eczema getting worse during summer?
In 2023, Canada experienced more than 6,000 wildfires that burned over 16 million hectares of land — an area larger than the entire state of Georgia. While far away from the devastation, the smoke reached across the US and more than 2,000 miles to Europe. Poor air quality from these distant wildfires caused eye and throat irritation and difficulty breathing.
In Boston, Dr. Arianne Shadi Kourosh, a dermatologist at Massachusetts General Hospital, also began to notice skin symptoms. Normally the dermatology clinics would see fewer than 20 people during a summer month for eczema, including atopic dermatitis. Suddenly that jumped to 160.
Looking back at summer month records from the last four years, her research showed that the number of visits for these skin complaints tracked with the severity of air pollution. These findings are consistent with other research noting an uptick in eczema flares and psoriasis flares associated with wildfire pollution. But why?
Researchers theorize that airborne pollutants might set off a cascade of effects within the body by activating an oxidative stress pathway. This damages the skin barrier and prompts an inflammatory response. This cascade also may play a role in the development of eczema.
What can you do to protect your skin?
Air pollutants in wildfire smoke may harm multiple organs — not just your heart and lungs, but also our skin, it seems. So, when outdoor air quality is bad due to wildfires, limiting your exposure can help reduce health risks. While we can say the same for industrial air pollution, wildfire pollution is likely worse due to its additional toxic particles.
- Seek help if you’re itching. Check with a dermatologist or your health team if you think wildfire smoke or other forms of air pollution might be affecting your skin.
- Check local air quality.AirNow.gov shares local, real-time air quality information and activity guidance. When recommended, stay indoors if possible. Shut doors, windows, and any outdoor air intake vents.
- Protect your skin. When you’re outdoors, wear a mineral-based sunscreen containing zinc or titanium. While most other sunscreens work through a chemical reaction to absorb the ultraviolet (UV) rays that damage skin, zinc and titanium sunscreens help by forming a barrier over skin that reflects off UV rays. The barrier also reduces the amount of pollutant particles getting to the skin to set off the inflammatory cascade. Wearing sunscreen protects against skin cancer, as well.
- Wash up. After coming back inside, cleansing your skin and applying a hypoallergenic moisturizer will help keep it healthy. If you do have eczema, choose cleansers and moisturizing products recommended by your dermatologist or health care provider.
About the Author
Wynne Armand, MD, Contributor
Dr. Wynne Armand is a physician at Massachusetts General Hospital (MGH), where she provides primary care; an assistant professor in medicine at Harvard Medical School; and associate director of the MGH Center for the Environment and … See Full Bio View all posts by Wynne Armand, MD
A hot weather plan is essential to staying healthy
Here’s a new fact about spring, summer, fall, and sometimes even winter: now that climate change has blurred seasonal boundaries, sizzling heat may be on the way, or currently blanketing your community.
High temperatures stress the body, leading to thousands of heat-related illnesses and deaths every year in the US. Creating a personal heat plan can help you stay safe when the heat index soars.
Caleb Dresser, MD, MPH, is the health care solutions lead for C-CHANGE, the Center for Climate Health and the Global Environment at the Harvard T.H. Chan School of Public Health, and an emergency medicine doctor at Harvard-affiliated Beth Israel Deaconess Medical Center. Below we interview him about who, how, and why heat harms. Then we’ll help you create your personal heat safety plan.
Interview edited for clarity
Who is especially vulnerable during hot weather?
High temperatures can affect anyone. But some people — children, outdoor workers, people who are pregnant or have health problems or disabilities, and older people — are more likely to experience harm when temperatures rise. For example:
- Young children, especially babies, have less physical capacity to deal with very high temperatures.
- People working outdoors may not have access to shade and could be performing physically intensive labor. They need adequate hydration, adequate breaks, and access to a cool space during break time, as OSHA guidelines spell out.
- People with chronic medical conditions, such as kidney disease or heart disease, may have difficulty adapting physiologically to hot weather, or may be more susceptible to its health impacts.
- And some people living with disabilities or certain neurological conditions may have difficulty with thermoregulation — that is, controlling the temperature of their bodies — or may not be able to take actions that keep them safe, such as taking off layers or moving to a cool area.
Which weather patterns create dangerous levels of heat?
Dangerous heat is the result of both high temperatures and high humidity, which interfere with our ability to cool off by sweating. In dry areas, extremely hot temperatures can be dangerous on their own.
Danger zones vary across the United States and around the world. But hospital use and deaths rise once we get above threshold temperatures. The threshold varies in different places depending on whether bodies, cultures, and architecture are adapted to heat.
For example, here in New England, where some people (particularly those of limited means) may not have access to air conditioning, we see increases in healthcare use and deaths at a lower temperature than in the American South, where people and organizations may be more used to dealing with hot weather.
When does hot weather become dangerous to our health?
Risk goes up the longer hot weather sticks around.
One hot day can put some people at risk. A stretch of several hot days in a row during a heat wave is particularly dangerous because it can overwhelm people’s ability to adapt. Eventually people run out of physiological reserves, leading to greater health harms and greater need for medical care.
Surprisingly, spring and early summer are particularly dangerous times because people and organizations aren’t as prepared for hot weather.
How to create your personal heat safety plan
Five key points to help you create a personal heat plan are below. Americares offers further information through heat tip sheets developed with the Harvard C-CHANGE team that are tailored to people in different health circumstances.
Planning is important because intense heat is occurring more often: a Climate Central analysis found 21 additional risky heat days, on average, for 232 out of 249 locations between 1970 and 2022.
- Stay ahead of hot weather. Check apps, websites, TV, or radio for updates on weather today and in coming days. If local weather alerts are available by phone or text, sign up.
- Have a cooling plan. When temperatures soar, you need to spend as much time as possible in cool spaces. Plan options if your home is likely to be too hot and unsafe to stay in. You may be able to stay with a neighbor or family member who has air conditioning until a heat wave passes. Many cities and towns have neighborhood splash pads for children, and open cooling centers or air-conditioned libraries, public buildings, or community centers to everyone — sometimes even overnight. Spending time in air-conditioned businesses or malls, or in a shady green space like a park, may help too.
- Sip plenty of fluids. Water is the best choice. Skip sugary drinks and avoid caffeine or alcohol.
- Use fans correctly. Fans help if surrounding air is relatively cool. If air temperatures are very high, it’s important to dampen your clothes or skin to help keep your body from overheating, and move to a cooler location, if possible.
- Know your personal risks and the signs of heat-related illness. If you have health problems or disabilities, or take certain medicines such as diuretics, talk to your doctor about the best ways for you to cope with heat. It’s also essential to know the signs of heat-related illnesses, which range from heat rash and sunburn to heat cramps, heat exhaustion, and heat stroke. This chart from the Centers for Disease Control and Prevention describes the signs to look for and what you can do, particularly when heat becomes an emergency.
About the Author
Francesca Coltrera, Editor, Harvard Health Blog
Francesca Coltrera is editor of the Harvard Health Blog, and associate editor of multimedia content for Harvard Health Publishing. She is an award-winning medical writer and co-author of Living Through Breast Cancer and The Breast Cancer … See Full Bio View all posts by Francesca Coltrera
About the Reviewer
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD
Salmonella is sneaky: Watch out
Pop quiz: what is Salmonella? If you’ve ever had a run-in with this bacteria, you know it can cause a food-borne illness called salmonellosis, a form of food poisoning. But you may not know that Salmonella bacteria sicken an estimated 1.35 million people and hospitalize 26,500 every year in the United States. What’s more, it kills more total people than any other type of food poisoning.
And Salmonella bacteria can be sneaky — not only by triggering unusual complications, but infecting people in startling ways, says Dr. Elizabeth Hohmann, an infectious disease specialist at Massachusetts General Hospital. One patient she treated showed up with an abdominal aortic aneurysm — a dangerous bulge in the lower section of the body’s largest artery — that looked infected. Testing revealed a culprit some would find surprising: Salmonella.
“It’s just an interesting organism and it can be kind of scary,” she says.
How do people get infected by Salmonella?
Many of the foods Salmonella bacteria lurk in are raw or undercooked. Breaded raw chicken products like nuggets and chicken Kiev are one way it may reach your table. But a variety of foods have been implicated — including organic basil, cantaloupes, ground beef, nut butters, raw cookie dough, eggs, raw or unpasteurized milk, and flour.
Even small pets such as turtles and frogs, along with dog food, have contributed to Salmonella outbreaks in recent years.
You can also become infected by handling contaminated food and spreading the bacteria from your hands to your mouth. Additionally, you can spread it to others on your hands or even on your clothes without becoming sick yourself.
“It’s a bug that’s carried in stool and animal feces and is also present in the environment,” Dr. Hohmann says. “So it can set up shop in lots of different inanimate objects, soils, and machinery, especially in moist environments.”
What symptoms can Salmonella cause?
Most of the time, Salmonella infection leads to gastroenteritis, usually causing just an upset stomach, abdominal cramps, and diarrhea. These symptoms can start as soon as six hours after ingesting the bacteria. Typically, symptoms resolve on their own within two to three days.
Some people have such mild symptoms they’re barely noticeable. “The classic case might be a college student who eats a burrito from a sketchy place, gets sick for a couple of days, gets better, and doesn’t think anything of it,” says Dr. Hohmann.
Sometimes symptoms are more serious, such as severe abdominal cramping and bloody diarrhea, or unexplained high fever and marked fatigue. These symptoms require a call to your doctor.
How is salmonellosis treated?
Most people will get better on their own without any medicines. Replacing lost fluids by sipping water or electrolyte drinks to avoid dehydration will help.
Call a doctor if you have
- diarrhea and a fever higher than 102° F
- diarrhea that doesn’t improve after three days
- bloody stools
- vomiting so severe it prevents you from keeping liquids down.
Treating the infection with medicine comes with an annoying paradox, Dr. Hohmann says. If doctors decide to prescribe antibiotics, the person taking the medicine may shed the organism for longer than if they were never treated. “Then that person may have the opportunity — either through poor personal hygiene, sex, or working as a food worker — to spread it to others,” she explains. “It’s challenging.”
What complications can Salmonella lead to?
Some people get sicker with salmonellosis than others, with seemingly no rhyme or reason. But certain folks are especially vulnerable to serious infection, including:
- adults 65 and older
- pregnant women
- children under 5
- people whose immune systems are weakened by diseases (such as cancer) or treatments (such as immunosuppressing drugs).
A small percentage of those infected can have Salmonella in their blood, which can spread the infection to other parts of the body such as the urinary tract, bones, joints, or central nervous system (brain and spinal fluid).
And, like Dr. Hohmann’s patient with the abdominal aortic aneurysm, on rare occasions Salmonella can lead to unusual blood vessel complications in people who already have atherosclerosis, blockage of the arteries caused by plaque buildup.
“It’s not that common,” she says. “Many physicians are aware of it, so they take special care if Salmonella is found in a person with vascular disease.”
What steps can you take to avoid Salmonella?
While new USDA rules that take effect in 2025 may help fuel recalls of certain foods, we all can take steps to avoid the food poisoning, illness, and hospitalizations that Salmonella exposure can cause.
Dr. Hohmann and the CDC suggest these strategies:
- Using hot water and soap, wash cutting boards or plates on which you cut into raw foods — including vegetables and fruit — before using those surfaces for other purposes. If possible, use separate cutting boards for produce, meat, and fish.
- Refrigerate or freeze foods that are perishable, prepared, or left over within two hours to thwart salmonella growth.
- Always wash hands well with soap and water before preparing food and after contact with animals, using the toilet, or changing diapers.
- If you have a sick pet, take extra care handling its feces and wash your hands thoroughly afterward.
Take additional steps to help more vulnerable people stay healthy:
- Don’t let young children touch high-risk animals, such as turtles, frogs, chickens, or ducks. “And if you’re taking young children to a petting zoo, they should not be petting animals unless you can disinfect their hands immediately afterward,” she says.
- Older adults and those with compromised immune systems should take extra care to wash and cook foods thoroughly.
- People who have had a transplant (such as a kidney transplant) should not keep reptiles or amphibians as pets.
“You hate to make people paranoid, so that we’re washing our lettuce leaves with soap, but it’s worth thinking about these things, particularly if you have people in your household who are susceptible — which is an increasing number of people,” Dr. Hohmann says.
About the Author
Maureen Salamon, Executive Editor, Harvard Women's Health Watch
Maureen Salamon is executive editor of Harvard Women’s Health Watch. She began her career as a newspaper reporter and later covered health and medicine for a wide variety of websites, magazines, and hospitals. Her work has … See Full Bio View all posts by Maureen Salamon
About the Reviewer
Howard E. LeWine, MD, Chief Medical Editor, Harvard Health Publishing
Dr. Howard LeWine is a practicing internist at Brigham and Women’s Hospital in Boston, Chief Medical Editor at Harvard Health Publishing, and editor in chief of Harvard Men’s Health Watch. See Full Bio View all posts by Howard E. LeWine, MD