The first exposure to the virus may result in a blistering rash in the mouth and/or lips with a body-wide, flu-like illness. This first outbreak of cold sores is usually gone within 7-10 days, but it can last up to 20 days. The sores can also develop in other locations on the skin.

Blisters

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The symptoms of the first outbreak are:

    
  • A blistering, painful rash of small ulcerations across the lips, gums, tongue, and the inside of the mouth. This is more common in children.
  • Pain and blistering on the soft roof of the mouth, tonsils, and throat, which is more common in adults.
  • Flu-like symptoms:     
  • Sore throat
  • Fever
  • Decreased energy
  • Muscle aches and pains
  • Swollen glands in the neck
  • After these initial symptoms, the virus may lie quietly in the nerves until it is reactivated. This may happen due to stress or illness. Direct sunlight, a weakened immune system, and menstruation can also trigger reactivation.

    If reactivated, the virus will come out as a cold sore . A few days before the sore appears, you may notice some itching, burning, or pain in the area. Some people have outbreaks regularly. Some never have another symptom after the initial infection.

    The symptoms of an active cold sore are:

        
  • Small, painful, fluid-filled, red-rimmed blisters
  • After a few days, the blisters dry and form a scab
  • Scabs heal in about five days, usually without scarring or loss of sensation