Bathing in warm sulfur spring water has been practiced for centuries for its potential health benefits, but a newly recognized cause for a sudden skin rash is exposure to this water. Unfortunately, it can cause a severe rash in some susceptible individuals.
This is especially true in allergic people who may tend to have dry skin or eczema.
Typically the rash appears suddenly about 24 hours after the water exposure. The rash is red with “punched out” ulcers and pits. The rash is caused by the acidic nature of the hydrogen sulfide, sulfate and sulfur that are in the water.
Many of the aquifers here in Florida are rich in these natural sulfur compounds.
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.