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Cold sores

A cold sore is a small collection of blisters that usually appears on the face - specifically around the lips. It’s caused by the herpes simplex virus.

Cold sores are contagious from when the first symptoms appear, to after the lesion has completely resolved.

Cold sore symptoms may not appear immediately after infection, and the first eruption of a cold sore may be quite some time later. But the virus stays in the body forever once infected, and it can cause further eruptions of cold sores at various times.

Cold sore eruptions can be random, but they’re also often triggered by certain factors such as:

  • Fatigue
  • Stress
  • Strong sunlight
  • Other illnesses and infections
  • Trauma to a certain part of the face
  • Menstrual periods
  • A tingling, itching or burning sensation
  • Followed by small, fluid-filled blisters
  • Followed by crusting as these blisters burst

Cold sores are particularly common around the edges of the lips, but can occur anywhere on the face. Symptoms of cold sores typically appear in the order above.

Cold sores usually get better on their own within 7-10 days.

If applied early (as soon as the first symptoms of tingling start), antiviral creams, bought from a pharmacy, can be effective. These should be applied to the area affected by the cold sore.

For more severe cold sore cases, or for people who develop recurrent episodes of cold sores, antiviral tablets can be prescribed by a GP. Again, to be effective, these need to be taken as soon as symptoms first appear.

Here are some simple cold sore remedies:

  • Avoid touching a cold sore (unless applying cream)

  • Dab cream on, rather than rubbing it in

  • Avoid the possible trigger factors mentioned above

  • Use paracetamol or ibuprofen for pain if needed

  • Avoid acidic and salty foods – as these may aggravate the cold sore and cause discomfort

  • To prevent spreading the infection to others:

  • Wash your hands after applying any cold sore cream or touching your cold sore

  • Don’t share anything that touches your face, like towels, cutlery, food, makeup or cold sore cream with anyone else

  • Avoid kissing and oral sex until the cold sore has completely healed.

  • You’re in a lot of discomfort, or the cold sore is stopping you from eating and drinking
  • The cold sore has spread or developed close to your eye
  • You’ve not seen any improvement in the cold sore after 10 days
  • You have inflamed and painful gums as well as the cold sore
  • You have a weakened immune system or are on chemotherapy.
Last updated:
12 Nov 2020
Reviewed by:
Dr Rhianna McClymont, Lead GP at Livi