There is no cure for cold sores. The herpes simplex virus hides deep in nerve roots and cannot be wiped out by medicines that are currently on the market. Most people will continue to get cold sores off and on throughout their life.
Herpes can be spread from a cold sore to another area of the body, which is called "autoinoculation." For example, touching a cold sore on the lip can cause herpes of the finger (herpetic whitlow). Autoinoculation occurs most commonly at the time of primary infection when viral shedding is high and the immune system is still gearing up to contain it. The antibodies that are made after primary infection are usually but not always successful in preventing autoinoculation during recurrent attack. For this reason, it is important to wash hands after touching the sore.
A more serious complication is ocular herpes, which causes sores and severe pain around the eye. Ocular herpes is also caused by autoinoculation. If not treated, ocular herpes can lead to serious damage or even blindness.
Sources www.emedicinehealth.com