Prevent the

If you crank up your car seat heater, you should take note of a study published in the Archives of Dermatology that reveals a downside to this luxury feature. Doctors have discovered that car seat heaters can mark your skin—for life.

Erythema ab igne (aka EAI) is a condition caused by chronic exposure to infrared radiation. This condition, conventionally known as "toasted skin syndrome," is caused by repeated exposure to heat at too low a level to burn you, but hot enough to cause hyperpigmentation in your skin. The condition is characterized by a lacework or net-like pattern of red or brown marks. The skin begins to thin and atrophy, and in severe cases itchiness, burning, or sores can occur.

Toasted skin syndrome is not a common condition in the U.S., where centralized heating is widely employed. EAI is more common in cultures where people spend a lot of time in front of an open fire or stove. However, certain low-level heat sources that can lead to EAI are common in the U.S., including laptops, heating pads, and hot water bottles. Seat heaters are now added to this list.

This doesn't mean that you should necessarily stop using your heater entirely. In the cases documented by this study, the subjects in question used seat heaters regularly and for 45 minutes or more at a time. Doctors suggest that you keep heaters on low settings and avoid prolonged exposure. If you do see any signs of discoloration, discontinue use of car seat heaters immediately.

The main way to treat toasted seat syndrome is to stop using the heat source. Over time, mild cases will resolve themselves and the marks will subside. However, if the hyperpigmentation is severe, the skin damage may be permanent. Laser therapy can also help reduce the appearance of the skin pigmentation. Extreme cases of EAI have been linked with higher incidences of squamous cell carcinomas, so regular skin cancer screenings of the area are crucial, especially if sores or lumps form.




Adams, Brian B., MD, MPH: "Heated Car Seat-Induced Erythema Ab Igne." Archives of Dermatology. Vol 148, No 2.. "Erythema ab igne" New Zealand Dermatological Society. Web. July 1. 2011.