These sores are caused by the herpes simplex virus. Once a person has been infected, the virus lies dormant in other nerves supplying sensation to our face. Certain triggers reactivate the virus and nasty cold sores appear on the lips or surrounding areas.

The following can trigger a cold sore onset.

• Emotional stress and exhaustion
• Pregnancy
• Exposure to sum light/sunshine or use of sunbeds
• Menstruation
• An injury to the mouth
• Some dental treatments
• Trauma to the face or lips
• A depressed immune system

Treatment

Treatment should start as soon as the tingle stage begins. If caught in time the cold sore can stay for only half the time.

Apply an antiviral cream to the sore even if the blister has appeared. The cream will help prevent the virus from spreading to another area.