HOT WATER bottles are a cheap and effective way to keep warm during the winter months. But holding one close to skin for long periods of time could lead to a skin condition, and even cancer. Hot water bottles prove very useful when it’s cold and are a popular choice for reliving aches and pains. But prolonged exposure has been found to trigger erythema ab igne - also referred to as a hot water bottle rash. Evidence has shown a link between the health condition and cancer, so does this mean we should stop using them? What is erythema ab igne? Erythema ab igne is a skin condition which happens when there is prolonged exposure to heat (like when a hot water bottle is pressed onto an area of skin). It’s characterised by mottled-looking skin and some people may complain of mild itchiness and a burning sensation. Other types of heat sources can also cause the condition, such as repeated exposure to heated car seats and resting a laptop computer on the thigh. What does research have to say A study carried out by researchers from the Department of Dermatology at University Hospital Basel, Switzerland, concentrated on erythema ab igne and laptop use. The case report was of a boy who had presented to the emergency department with marks on one of his upper legs. The researchers also carried out a literature search for studies of similar cases in a review of the topic. They found that nine cases of laptop-induced erythema have been reported since 2004, plus one case of a burn produced by a laptop. The researchers said it was possible that the skin damage could develop into burns, as mild to moderate heat between 43 and 47C is enough to result in burns. They also suggested a small risk of skin cancer developing in the long term. What do doctors have to say? Dr Andrew Thornber, chief medical officer at Now Patient, advised that if the area of skin has been mildly affected, it should disappear within a few weeks or months. If severe and pigmentation has been caused, the marks may stay for some years. He added: “In more serious cases of erythema, the skin can be left darkened, although not usually permanently. “There is evidence to indicate it can lead to cancer, as occasionally, the first sign of splenomegaly, pancreatitis, pancreatic cancer, and other cancers is erythema ab igne resulting when patients apply external heat to relieve the underlying pain.” Treatment Depending on the severity, erythema ab igne can be treated. Dr Thornber advised: “Yes, it can be, depending on the severity. “Stopping using a hot water bottle, especially on the affected area is recommended. “Treatment with topical tretinoin or laser may improve the appearance.” Source