I’m sure many of us use Laptops, and as the name suggest they are supposed to be placed on your laps. But have you ever thought that long term placement of laptops on your laps can cost you much. Yes, placing laptops on your laps without any cooling device or barrier can cause a skin condition called erythema ab igne, commonly known as toasted skin syndrome, fire stains or laptop thigh. Since the development of laptop computers, it has been a major risk factor for erythema ab igne and is increasing dramatically among the individuals who are prolonged laptop users.

Who Gets Erythema ab Igne?

Previously it was a common condition of elderly individuals and women, who are more prone to heat exposure. It was commonly seen on sins among the house-wife who were frequently involved in cooking on wood-burning stoves or close to fires. Other risk factors were those people who use electric heater, hot water bags or heating pads for joint pain or lower back pain. It can also be seen on the arms of chefs and bakers who are often exposed to the heat and radiation from ovens, as well as in glassmakers and jewelers. People with underlying conditions like hypothyroidism and poor microcirculation are more prone to this condition.

With the development of laptops computers it has been a major concern since heat and infrared radiation can directly affect the thighs. The underside of a laptop can be above 50 celcius, which is much warmer than you might have imagine and is enough to cause erythema ab igne when exposed for prolonged time. The heat and radiation source can be the fan, the battery or the optical drive.

How does it look like?

Initially, there may be mild and transient redness on the affected area. After prolonged repetitive exposure, the characteristics rash of erythema ab igne develops. The rash of erythema ab igne looks like reticular (net-like), red to brown pigmented patch on the area that has been affected by prolonged heat or radiation. In some cases there may be mild itching and burning sensation but most often it may be asymptomatic and go unnoticed until one see it.

Erythema ab Igne and Cancer

Although most experts agree on the fact that erythema ab igne due to laptops may not cause any long-term side effects or lead to severe complications, there is still a small chance of malignant transformation. Few papers have suggested that, on rare occasions, squamous cell carcinoma and Merkel cell carcinoma may arise in the lesions of erythema ab igne, but it may take more than 30 years of chronic exposure.[1-4] So, individuals with a history of long-standing erythema ab igne should consult dermatologist for detail examination and if needed the area should be biopsied.

Treatment of Erythema ab Igne

The treatment of erythema ab igne is to avoid exposure to heat and radiation source. You may need to add something in between your laptop and the leg to prevent further damage to the skin. The rash will ultimately fade and return to normal several months after discontinuation of direct heat or radiation. However in dark skinned individuals there may be pigmentation abnormalities that might take longer than normal or even permanent. So, the earlier you start preventing the more chances of complete recovery.

Hyperpigmentation can be improved with the use of topical agents like hydroquinone or tretinoin. If there is itching and inflammation mild corticosteroids may be applied.

Prevention of to
  • Avoid using laptops on naked thighs.
  • Add some cooling fan or any other barrier in between your laptop and the leg.
  • If possible try to avoid further heat exposure by placing the laptop on the desk.


  1. Cross F. On a turf (peat) fire cancer: malignant change superimposed on erythema ab igne. Proc R Soc Med 1967;60:1307-8.
  2. Peterkin GA. Malignant change in erythema ab igne. BMJ 1955;2:1599-600.
  3. Jones, CS, Tyring SK, Lee PC, Fine JD. Development of neuroendocrine (Merkel cell) carcinoma mixed with squamous cell carcinoma in erythema ab igne. Arch Dermatol 1988;124:110-3.
  4. Hewitt JB, Sherif A, Kerr KM, Stankler L. Merkel cell and squamous cell carcinomas arising in erythema ab igne [letter]. Br J Dermatol 1993;128:591-2.