What are they?
These are blisters that appear on the lips and around the mouth. Cold sores are caused by the herpes simplex virus (HSV), thus are also called herpes labialis.
There are two types of HSV namely HSV-1 and HSV-2. The former is mostly responsible for this condition, though both types can cause it.
How do they occur?
HSV-1 usually enters through the mouth or occasionally through the skin during contact with an infected person. The very first infection may go unnoticed or produce a severe reaction leading to very painful ulcers in the mouth. Thereafter, the virus remains dormant or latent until reactivated by such things as febrile illnesses, stress, trauma and ultraviolet radiation. Recurrent attacks can occur throughout life, and may be up to six times in a year.
You can pass the virus to other people through your saliva when you have cold sores. To reduce this risk, avoid kissing or oral sex during this period and don’t share cutlery and other personals like towels.
What are the symptoms?
There may be a brief period of tingly feeling or increased sensation on the lips. This is followed by the appearance of red patches which then become small blisters. When the blisters burst, the skin becomes an open sore. Fever may also occur. The skin returns to normal in about seven to ten days even without treatment.
Cold sores can be complicated by an infection of the skin around the nails (whitlow), spread to the eyes and into the brain.
What treatments work?
Cold sores usually clear up without any treatment in seven to ten days, but you can try to shorten their duration when they occur. There is currently no evidence to show that antiviral creams prevent these cold sores from coming, but sunscreens may help in situations when the recurrence is triggered by sunlight. The doctor will prescribe a special type of antiviral drugs that are effective against HSV infection. Aciclovir is commonly used, but foscarnet is better in people with a weak immune system such as occurs in HIV.