Amid rising energy costs in many parts of the world, people will be turning to hot water bottles on colder days. — dpa
Is there anything cosier in cold weather than curling up with a hot water bottle or some other cuddly heat source?
Heating pads, electric blankets and the like are very popular with some of us, especially if we’re keeping the thermostat low because of soaring heating costs.
But their toasty warmth can leave us literally toasted: in the form of possibly irreparable skin damage.
So while it can be very pleasant to use a heatable pillow for abdominal pain, a heat patch for an aching back, and a hot water bottle for menstrual cramps – or simply to fall asleep with – be careful not to overdo it.
At temperatures between 40 and 50 degrees Celsius, brief contact of a heat source with your skin won’t cause burns, says Dr Friederike Wagner, a dermatologist at the Dermatologikum clinic in Hamburg, Germany.
But “regular, deep heat” can discolour the skin, resulting in a reddish-brown, reticular – or net-like – rash.
The scientific name of this hyperpigmentation is erythema ab igne (EAI), which is derived from Latin and Greek and can be translated as ”redness from fire.”
More commonly, it’s known as toasted skin syndrome.
However you call it, the condition manifests itself solely in visible changes to the skin, Dr Wagner says.
Although few studies have been done on EAI, it’s thought that recurrent, moderate heat can damage superficial blood vessels, which initially dilate, causing the skin to redden, says Munich-based dermatologist Dr Esther Wissmüller.
When the vessels become damaged, red blood corpuscles leak out.
Their decomposition product, an iron-containing protein known medically as haemosiderin, forms deposits in the skin.
This, says Dr Wissmüller, is what discolours it.
”If the application of heat is repeated and prolonged, the skin changes become chronic,” Dr Wagner explains.
“This means that the EAI is permanent and won’t go away.”
The condition is typically painless and also otherwise asymptomatic.
If the skin does, however, itch or produce a burning sensation, it can be treated with a cream or ointment.
Despite the benign nature of EAI, you should see a dermatologist if a reddish-brown web pattern appears on your skin, as there are serious illnesses that can look very similar.
EAI can be easily prevented – simply by not exposing yourself to deep heat too often.
But what’s too often?
It’s hard to say.
Spending a few evenings with a hot-water bottle is hardly likely to lead to EAI, notes Dr Wagner.
Too little is known about the role played by genetic predisposition though, and about the length of heat exposure required to discolour the skin.
Particularly people who often go to sleep with a hot-water bottle or wear a heat patch on their back should therefore have their skin examined regularly by a dermatologist.
EAI can be caused by any kind of deep, prolonged heat, Dr Wagner warns, be it from a hot water bottle, electric blanket, heated car seat or hot laptop computer resting on your lap.
The heat may feel good, but you’re asking for trouble if you make it a habit. – dpa
