Technically, toasted skin syndrome is called erythema ab igne, but it’s also known as “laptop-induced dermatosis” and “fire stains”.

Symptoms

Toasted skin syndrome is a red-brown mottled rash. Under a microscope, the affected skin resembles skin damaged by long-term sun exposure. The skin and underlying tissue may start to thin and sometimes sores or lesions develop. Some people complain of mild itchiness and a burning sensation, but it often goes unnoticed unless a change in pigmentation is seen.

Cause

This condition is caused by the slowing of blood flow in the affected area (hemostasis) because of prolonged exposure to heat, without an actual burn. Sources of heat include the following:

    • Resting a hot laptop on your lap for an extended period
    • Repeated application of hot water bottles or heat pads to treat chronic pain, for example chronic backache
    • Repeated exposure to car heaters or furniture with built-in heaters
    • Occupational hazards such as silversmiths and jewellers (faces exposed to heat), and bakers and chefs (arms exposed).

It may also be seen in people with hypothyroidism and lymphoedema.

Effect

Toasted skin syndrome is generally harmless but can cause permanent skin darkening. In very rare cases, it can cause damage leading to skin cancers. Children are especially vulnerable, as their skin is more sensitive than the skin of adults.

A medical report found that men who used laptops on their laps had elevated scrotum temperatures. If prolonged, this could decrease sperm production that could potentially lead to infertility.

Treatment

If the area is only mildly affected with slight redness, the condition may resolve by itself in a few months, but if the condition is severe and the skin pigmented and atrophic, resolution is unlikely and you should see a doctor. In this case, there is a possibility that squamous cell carcinomas may form. If there is a persistent sore that doesn’t heal or a growing lump within the rash, a skin biopsy should be performed to rule out the possibility of skin cancer. Abnormally pigmented skin may persist for years. Treatment with topical tretinoin or laser may improve the appearance.

Prevention

Remove the source of heat. In their user manuals, major laptop manufacturers warn against placing laptops on laps or exposed skin for extended periods because of the risk of burns.