Toasted Skin Syndrome: What It Is and What To Do (2025)

Toasted skin syndrome (known clinically as erythema ab igne) causes a lattice-like rash after long-term skin exposure to infrared radiation or heat. Common causes include using laptops or heating pads, or sitting too close to space heaters or radiators.

Though this condition is relatively mild and typically resolves on its own, researchers have linked toasted skin syndrome to certain types of skin cancer. It's important to recognize the symptoms and, when needed, be proactive about treatment.

What Causes Toasted Skin Syndrome?

Skin exposure to moderate heat, typically below 113 degrees Fahrenheit, causes toasted skin syndrome. The heat is not hot enough to burn the skin, but can cause a reaction.

Several devices and heating technologies trigger this condition, including:

• Heated seats: Heated car seats can trigger this condition in the areas contacting the seat, namely the lower back and back of the thighs.
• Heating pads/electric blankets: Many cases of toasted skin syndrome are caused by heating pads or electric blankets, even causing symptoms when on mild or moderate settings.
• Hot-water bottles: Toasted skin syndrome symptoms can arise from use of hot-water bottles, commonly used to manage muscular, bone, or joint pain.
• Industrial work: Exposure to fires and heat at work, as with metalwork, coal mining, and other industrial jobs, can cause this issue.
• Laptops: Laptop lithium batteries can get as hot as 130 degrees, and over time, working with a computer on your lap can cause symptoms of toasted skin on the thighs.
• Ovens and stoves: Blasts of heat from ovens and hot stoves can cause toasted skin syndrome on parts of the body most exposed, namely the arms and face. Early scientific literature has reported cases in people using woodstoves.
• Radiators and heaters: Spending too much time near space heaters and radiators can trigger this condition. The number of cases has dropped with advances in technology like central heating.

Researchers do not fully understand what happens to the skin with toasted skin syndrome. They believe the rash is caused by damage to blood vessels, skin cells, and supporting fibers. The skin darkens due to the build-up of skin pigments, particularly hemosiderin—a brown pigment—and melanin.

Skin Symptoms

Toasted skin symptoms occur in areas that are exposed to heat. How they present varies from person to person. Signs of this condition include:

• Itching and stinging: Some people experience itchiness, burning, or stinging pain, which isn’t always a symptom.
  
• Lesions:Blisters can form over affected areas and leak fluid or form crusts.
• Patterned rash: Initially, a blotchy skin rash and discoloration form in the areas exposed to heat. Over time, a distinct, lattice or fishnet pattern forms.

How Toasted Skin Syndrome Is Diagnosed

In many cases, evaluating the physical signs of toasted skin syndrome and assessing health history and status are enough for a healthcare provider to make a diagnosis. They will ask about heat exposure and carefully examine the affected areas visually and by touch.

If it’s difficult to determine the cause of symptoms, your provider may recommend abiopsy.During this procedure, a healthcare provider, such as a dermatologist (skin specialist), scrapes off a small sample of skin tissue and sends it to a clinical laboratory for analysis.

Pathologists (specialists in identifying diseases) use high-powered microscopes to examine the tissue for signs of cancer or other diseases.

How to Treat

There is no established treatment protocol for toasted skin syndrome, and no singular cure.

If you eliminate the heat source, the symptoms usually heal on their own, though this can take weeks to months. Some may develop permanent symptoms.

Depending on the case, treatments for this condition may involve:

• Topical (applied to the skin) bioflavonoids (vitamin C), retinoids (vitamin A)
• Prescribed topical medications like 5-fluorouracil (5-FU) or hydroquinone
• Prisma (mesoglycan), an oral medication
• Laser therapy, for severe cases that cause permanent skin color changes
• Medical monitoring, keeping an eye on the progress of the rash
• Applying aloe or lotions with retinol to affected areas for symptom relief

Prevention Tips

The main way to prevent toasted skin syndrome is to identify what is causing it and prevent prolonged exposure.

Steps to take include:

• Not using electrical blankets, or only using the lowest setting
• Not applying heating pads or hot water bottles directly to the skin
• Not sitting too close to space heaters or radiators, keeping a distance of at least 2 feet
• Using lower heat settings on space heaters and setting timers so they shut off automatically.

Healing Complications and Long-Term Changes

Most cases of toasted skin syndrome resolve on their own. Rarely, the cellular changes in the skin due to this condition lead to more serious complications, including:

• Basal cell carcinoma (BCC): The most common skin cancer, BCC causes slow-growing bumps on the skin.
• Cutaneous lymphoma: A lymphoma is a cancer that affects T-cells, a type of white blood cell, in the skin, leading to raised scaly patches, round rashes, and other growths.
• Hyperpigmentation: Sometimes, the color changes in the skin become permanent, despite removing the heat source and treatment.
• Merkel cell carcinoma: Fast-moving and aggressive, this rare skin cancer causes a painless, shiny bump on the skin.
• Squamous cell carcinoma (SCC): The second most common type of skin cancer, SCC causes scaly, discolored patches, rough or thick skin, and open sores.
  

When to See a Provider

Seek medical care if the following occur:

• Your burns are not healing properly.
• You experience itchiness or pain.
• The rash spreads or otherwise gets worse.
• You notice changes in the size, shape, thickness, or texture of the rash.
• Symptoms cause emotional distress, affect your confidence, or hinder your quality of life.

Summary

Toasted skin syndrome, or erythema ab igne, is a rash caused by moderate heat exposure. It causes a lattice-like pattern of skin discoloration and other symptoms, like skin itchiness or stinging.

Using heating pads or electric blankets, sitting too close to space heaters or radiators, and using laptops on the lap are reported causes of this condition. Most cases resolve independently, with medications and other treatments taking on chronic cases. Rarely, toasted skin syndrome can develop into skin cancer.