Toasted skin syndrome, known medically as erythema ab igne, is an uncommon skin condition caused by long-term exposure to a low-level heat source, like a heating pad or space heater. The heat is just enough to cause minor damage to the surface of the skin, but not enough to cause a burn.
Toasted skin syndrome causes visible changes to your skin, typically after weeks or months of repeated exposure to a heat source. These changes affect the area of skin that has been exposed to heat, and may include:
- A discolored, darkened, or reddened rash in a web-like or fishnet pattern
- Itching
- Burning
- Stinging
- Scaliness
Reproduced with permission from © DermNet dermnetnz.org 2025.
Repeated exposure to a heat source causes toasted skin syndrome. Experts believe that frequent exposure to heat causes parts of the outer layer of skin, including blood vessels and elastic fibers, to break down. This triggers a release of melanin, the pigment that gives skin its color, which causes the hyperpigmentation (excess redness or discoloration) to form.
Common sources of heat exposure that may cause toasted skin syndrome include:
- Heating pads
- Heated blankets
- Seat warmers
- Laptops and other electronic devices
- Space heaters, radiators, and fireplaces
- Certain work environments, including commercial kitchens and industrial factories
Risk Factors
Anyone can get toasted skin syndrome from exposure to a heat source, but some people are more at risk than others. This includes people who:
- Regularly use heating pads for pain relief
- Place their laptops on their legs while using them
- Have regular exposure to indoor heating sources like wood stoves, radiators, and fireplaces
- Work in kitchens or factories where heat is used to manufacture or prepare goods
- Commute long hours while using a seat warmer
Diagnosing toasted skin syndrome is fairly simple: A doctor will likely examine your skin, then ask questions about your medical history and any recent exposure to heat. If you have the characteristic net-like rash and report regular or prolonged exposure to mild heat in that same area, no further testing is usually needed.
A doctor may also recommend a skin biopsy. This means that a small sample of the outer layer of your skin will be removed and sent to a laboratory for examination under a microscope. A biopsy can help your provider rule out other causes of your symptoms.
Treating toasted skin syndrome primarily involves decreasing or stopping your exposure to the heat source. With less exposure, the skin typically heals on its own over several weeks or months.
If your skin discoloration persists, consider scheduling an appointment with a dermatologist. You may be able to treat lingering discoloration with laser therapy treatments or topical tretinoin. Both help decrease the amount of pigment in the skin.
While a dermatologist can recommend treatment, toasted skin syndrome can cause permanent discoloration and scarring in some people. You may not be able to get rid of the rash completely.
You can avoid toasted skin syndrome by putting enough space between your skin and nearby heat sources. Some best practices for preventing toasted skin syndrome include:
- Limit the time you spend applying heat from heating pads, heated blankets, and seat warmers directly to your body.
- Sit far enough away from heat sources like radiators, space heaters, wood stoves, and fireplaces.
- Wear protective clothing when working around industrial heat sources or kitchen stoves, grills, and ovens.
- Keep laptops and other electronics on desks or tables rather than directly on your body.
If you have toasted skin syndrome, continuing to expose that part of your body to heat sources can increase your risk for some skin cancers. Over time, heat can damage your cells and cause inflammation, which may lead to the growth of cancer cells.
The most common types of skin cancers seen in people with chronic toasted skin syndrome include:
- Squamous cell carcinoma: A common cancer that affects one of the three types of cells that make up the top layer of skin.
- Merkel cell carcinoma: A rare and aggressive kind of cancer that affects cells deep in the top layer of skin.
- Basal cell carcinoma: The most common type of skin cancer, basal cell carcinoma affects one of the three types of cells that make up the top layer of skin.
- Cutaneous marginal zone lymphoma: This is a rare cancer that develops in specific cells found in the second layer of skin.
Most cases of cancer associated with toasted skin syndrome occur decades after symptoms began—it’s important to see a dermatologist for regular skin checks if you’ve had this condition, even if it completely disappears and you no longer have symptoms.
