Dear Dr. K: In one of your old newsletters you wrote about a computer rash. I think I have developed it but I can’t remember the details.
The condition is called Erythema Ab Igne. The rash is a lacy reticular redness that has a mild itch or burning sensation. It can also be mildly tender to the touch. It is caused by chronic exposure to an external heat source. In the article you mentioned I discussed how chronic laptop computer, actually sitting on the lap, can cause the rash to appear on the thighs.
This has been described in a wide variety of situations including use of hot water bottles, heating pads, electric blankets, space heaters, car heaters, hot bricks, infrared lamps, wood and coal stoves.
The rash is not a burn and can only occur with repeated exposure to the heat source. Similarly, the rash doesn’t immediately go away with cessation of the exposure. It can take months for it to resolve.