There is a allergy called Cold urticaria. With this illness, some people on being exposed to very cold condition develop hives – a big red rash that itches constantly – or welts (a raised rash0 on the skin. Sometimes the hands and feet will also become swollen. Usually these will go away by themselves, but they can last for over 6 weeks and with some people they keep coming back. It is not really known what causes this allergy, only that in some people the cold sets off the release of histamine (similar to the cause of hay fever and other allergies) which gives an allergic reaction.
For most people this condition is annoying and unpleasant, but soon over. However, for a small number of sufferers the symptoms are really bad and seriously interfere with their quality of life. For example, one boy in Canada was in so much pain, with his hands and feet turning purple and swelling a lot, that his parents took him to hospital – however, he warmed up in the car and when they got there the symptoms were gone. Then, of course, next time he went out in the cold the same thing happened again.
Where the allergy is really bad, a person may have to remain indoors nearly all the time during the winter months – which in northern countries can mean a very long time – and they can’t swim except in a very well heated pool or even have ice cubes in their drinks. Where the symptoms are so extreme, people have tried all sorts of things including wearing an allergy mask, but there is no real proof that this would help.
There is not much successful treatment for this allergy. Sufferers usually find the best thing is to keep a warm, constant temperature and try to avoid sudden exposure to cold – even air conditioning can trigger an outbreak. People do sometimes try spreading butter or creams on their skin, and some take antihistamines, whether in the form of creams or as medication, but these aren’t specifically for cold urticaria and evidence that they really work is shaky. Keeping warm is definitely the main thing.
It also helps to know what kind of situations are likely to cause an allergic reaction. Obviously, a cold winter’s day is the most common trigger. It should only be necessary to avoid the outdoors completely if you have a very severe allergy; for other sufferers, by dressing very warmly with lots of layers, and perhaps scarves as well, a short walk in the cold may be all right though longer ones would be best avoided.
Equally, very hot conditions can cause problems, especially if you sweat and then cool down – the sudden cold air can cause rashes to form. If you are in conditions where you sweat the best thing is to get somewhere warm and to dry yourself straight away.
Be very careful if you go swimming. Indeed, for severe allergy sufferers swimming is not recommended at all. However, as swimming has so many other health benefits, if your doctor agrees it is safe to swim you may like to try it – but you should never go alone in case your blood pressure drops suddenly (hypotension) making you too weak to swim. It is also recommended that you take a non-drowsy antihistamine medication before you go in, and try to warm up gradually.
Air conditioning is best avoided; at least you should take something like a cardigan to put on when the temperature drops. You should also try to avoid very hot or cold food or drink or sitting on a very cold seat.