Cold sores normally first occur on or near your lip. They are caused by a type of herpes virus that is highly contagious and are often caught in childhood from someone who is infected. The virus lies dormant until it is activated, usually at a most inconvenient moment, and starts by tingling or burning near where the blister is going to occur. Within a few hours one or more small blisters form, often swelling the surrounding area, giving rise to a throbbing painful sore.
The liquid inside the blister contains active herpes viruses, so may spread to other areas or other people once the blister breaks. The sore may become infected with bacteria as well as with the virus, so care must be taken to prevent any further infection.
Once you have had your first cold sore, you will remain infected, so there is no absolute cure. This is why, if you have never had a cold sore before, your best protection is not to get one in the first place, so take care when people around you have a cold sore. Try not to touch the infected person's cold sore and make sure you don’t share cups, cutlery, toothbrushes and towels. Ensure you (and they) wash and dry your hands frequently.
Once a person is infected, the cold sore virus often lies dormant for some time, and can be activated again by stress, sunburn, colds and flu’, by physical injury such as from dental work, or from fatigue and being run down. There are many different triggers and they can be different for different people. It is important to get to know what yours are so that you can treat your cold sore quickly.
The best treatment for cold sores is specific antiviral medicines, used at the first warning sign that cold sores are on their way. This warning is usually a tingling or burning sensation. These antiviral medicines are available at your local pharmacy and include tablets that are taken as soon as warning signs develop, and antiviral creams that are applied as soon as the warning signs are felt. Other treatment options like patches aim at healing and protecting the cold sores, as well as preventing their spread. There are also creams that can help with managing the pain and discomfort as well as preventing bacterial infections of the sore.
Most cold sores resolve within 10 days, but will return if you don’t prevent the triggers from activating the virus again. Your community pharmacist will be able to give you advice to treat and prevent reinfection of cold sores, and determine if you need to seek further medical help to prevent your cold sores developing into more serious infections.