Dermatologist for cold sores

Cold sores are caused by the herpes simplex virus, which is related to, but has nothing to do with, the virus that causes genital herpes (HSV-2). They can be spread by close contact – for example, through kissing. 

The primary infection is most likely to happen in younger children, under the age of 5, when the symptoms can be severe. They can include swollen gums, sores in and around their mouth, a sore throat and a temperature. After this the virus remains dormant, waiting to be activated. Any recurrent infection usually involves just cold sores. 

Some people are at more risk of getting them than others and factors such as stress or tiredness can also increase your risk of getting them repeatedly. Sunshine can decrease your skin's immune response, so holidays in the sun may trigger them. And women may find that they're more prone to them during their period.

Many people find that a cold sore reappears in the same place on the lips or around the nose. They may also spread to other areas.

In some cases, they can affect the eyes. If this happens you will need emergency treatment to prevent damage to the eye and you should go to the hospital immediately.

If you have eczema, the spread of the herpes virus can be rapid and involve large areas of the body. This is also a medical emergency and you'll need to go to the hospital for treatment.

Cold sores usually disappear within a few days without needing treatment. But over the counter antiviral creams – such as acyclovir – can help if you apply them as soon as you feel a tingling, before the sore appears. 

If you're particularly prone to cold sores triggered by the sun, then taking an oral antiviral tablet before going on a sunny holiday may help.

Recurrent cold sore treatment can include an oral form of an antiviral such as acyclovir. This may, however, mean taking the drug on a daily basis for many months or, in some cases, over a longer period.