text: A cold sore is a fluid-filled blister which usually appears at the edge of the lips. Cold sores are caused by a herpes simplex virus infection.\n\nWhile anyone can be infected by herpes virus, not everyone will show symptoms.\nThe primary infection can cause symptoms like other viral infections including tiredness, headache, fever, and swollen lymph nodes in the neck.\nBecause oral herpes is so common, it is diagnosed primarily by symptoms. It can be diagnosed and treated by the family doctor, dermatologists (doctors who specialize in skin diseases) and infectious disease specialists. Laboratory tests may be performed to look for the virus.\nTreatment\n\nThere is no cure for herpes virus infections. There are antiviral drugs available that have some effect on lessening the symptoms and decreasing the length of herpes outbreaks.\nAcyclovir (Zovirax) is the drug of choice for herpes infection and can be given intravenously or taken by mouth. It can be applied directly to sores as an ointment, but is not very useful in this form. A liquid form for children is also available. Acyclovir is effective in treating both the primary infection and recurrent outbreaks. When taken by mouth to prevent an outbreak, acyclovir reduces the frequency of herpes outbreaks.\n\nDuring an outbreak of cold sores, salty foods, citrus foods (oranges etc.), and other foods that irritate the sores should be avoided. Wash the sores once or twice a day with warm, soapy water and pat gently to dry. Over-the-counter lip products that contain the chemical phenol (such as Blistex Medicated Lip Ointment) and numbing ointments (Anbesol) help to relieve cold sores. A bandage may be placed over the sores to protect them and prevent spreading the virus to other sites on the lips or face. Acetaminophen (Tylenol) or ibuprofen (Motrin, Advil) may be taken if necessary to reduce pain and fever.\n\nAlternative treatment\n\nVitamin and mineral supplements and diet may have an effect on the recurrence and duration of cold sores. In general, cold sore sufferers should eat a healthy diet of unprocessed foods such as vegetables, fruits, and whole grains. Alcohol, caffeine, and sugar should be avoided.\n\nFoods rich in arginine that should be avoided are chocolate, peanuts, almonds, and other nuts and seeds.\nVitamin C and bioflavonoids (a substance in fruits that helps the body to absorb and use vitamin C) have been shown to reduce the duration of a cold sore outbreak and reduce the number of sores. The vitamin B complex includes important vitamins that support the nervous system where viruses can hide out.