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Cold sores

cold; sores; fever; virus; herpes; simplex;

Cold sores start off as small lumps under the skin surface, and after a day or so, small painful blisters appear. Cold sores usually appear on or next to the lips, or less often on the nostrils, chin or other parts of the face, and sometimes inside the mouth on the palate or gums.


You may not have had one for years, then one day you have a vaguely familiar tingling on your lip. You can’t see anything in the mirror, but you can feel a tiny hard lump. Perhaps it is your imagination. You go about your day, but the tingling becomes stronger. You get home that evening and inspect your lip in the mirror.

What you see there horrifies you. That vague tingling feeling has developed into a huge cold sore that seems to get worse by the minute. A virus that entered your body years before has lurked there patiently waiting for the right conditions to come back and taunt you. The name of that virus? Herpes simplex type 1! It is..... the return of the dreaded cold sore!

What is a cold sore?

  • Cold sores start off as small lumps under the skin surface, and after a day or so, small painful blisters appear.
    • There is usually a tingling feeling where the sore is.
    • The blisters break and ooze a little fluid, then a yellow crust forms over the lump.
    • Finally, about 7 to 10 days after the first tingling was felt, the crust falls off, leaving pinkish skin which heals without a scar.
  • Cold sores usually appear on or next to the lips, or less often on the nostrils, chin or other parts of the face, and sometimes inside the mouth on the palate or gums. They can form on any other parts of the body, including the genital area (genital herpes), although genital herpes is usually caused by a slightly different herpes simplex virus (type 2).

What causes cold sores?

  • Cold sores are caused by the herpes simplex virus which we catch once in our life.
    • Usually the infection comes from the saliva of someone who has an unhealed cold sore, but small amounts of the virus can be in the saliva of a person even when he or she does not have a cold sore.
    • The virus can be spread by getting saliva onto fingers and carrying it to the mouth or nose, or by sharing cups, eating utensils (spoons, etc.), razors or even possibly towels, and by kissing.
  • The first time you have an infection, usually there are no sores, but a few people become very ill with a lot of sores inside their mouth.
  • Once you have become infected, the virus stays in the nerves of the skin for the rest of your life, and you can get new cold sores at or near the same place as the first cold sore.

Triggers for new cold sores

  • In some people, the virus can stay 'dormant' or inactive, and they may never get another cold sore.
  • Other people may get the odd cold sore here and there, but some are less lucky, and may have cold sores regularly for many years.
  • For people who do get cold sores more often several things can trigger the virus into causing a cold sore, including stress, illness (fever), sunburn and hormonal changes (such as periods).
  • If your cold sores tend to break out after you have been in the sun, make sure you always use a hat and apply a good quality sun block on your face and lips.

Treating a cold sore

  • There is no cure for cold sores, but there are some things which may make the sore smaller or go away faster.
  • These need to be started as soon as possible, when you first get the tingly feeling and there is only a small lump. Starting treatment after the blister appears probably won’t work so well.
    • Cold sore creams and treatments available from chemists can be helpful in preventing the cold sore from erupting or helping it dry up more quickly. Antiviral treatments such as idoxuridine or aciclovir seem to be quite effective.
  • For pain you could try paracetamol or ibuprofen.
  • Let the sore heal by itself. Don’t squeeze it, or pick the crust off. The sores heal without scarring if left alone, but squeezing or picking off the crust can cause scarring.

Be extra careful about touching the cold sore and then touching your eyes. Spreading the infection to the eyes can actually lead to blindness, but fortunately this rarely occurs!

Preventing spread to others

  • When you have a blister, avoid kissing or skin contact with others, especially young children who have not had cold sores.
  • Don’t share cups, spoons, towels, or razors when you have blisters.
  • Keep your hands clean.

Mel says:

“Cold sores are a lot like zits. They always rock up at the worst times! If you are quick and start using the medication right away, it might not be too bad.

Of course you can’t get up too close and personal with your special friend, but you don’t have to stay home and be miserable either! Anyway cold sores, don’t last too long."


Your doctor or chemist can advise you on treatments and cold sore creams.


Annunziato P 'Herpes simplex virus infections' in Garfunkel et al 'Mosby's Pediatric Clinical Advisor' Mosby Inc 2002

Department of Health, South Australia ‘Herpes simplex type 1’  

Mayo Clinic 'Cold Sore'

Whitley RJ, Roizman B 'Herpes simplex virus infections' The Lancet Vol 357, May 2001 1513-18

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