General Information

Cold sores are caused by the herpes simplex type 1 virus. Most people carry this virus in their bodies, but not everyone will get cold sores.

People usually become infected with the virus during childhood. After a usually mild (or unnoticed) infection, the virus then lies dormant (inactive) in the nerves until it is reactivated and causes a cold sore.

Cold sores are usually found on or around the lips or nose, and inside the mouth, but they may occur anywhere on the body. They often appear in the same place each time.

Cold sores are easily spread from person to person, especially when the sore is still weeping. They can be spread by kissing and sharing towels.

Common triggers that can cause the virus to reactivate include:

  • having a cold or the flu
  • exposure to bright sunlight or windy conditions
  • emotional stress or being ‘run down’ or unwell
  • hormonal changes, including menstruation
  • operations on the face or dental work
  • dry, chapped lips
  • minor damage or injury to an area affected by cold sores in the past

When the virus is reactivated it travels down the nerve to your skin, where it multiplies. This often causes a tingling feeling in the area, which can be a warning sign a cold sore is about to appear. Other warning signs may include burning, pain, itching or numbness. These signs may appear within a few hours to a couple of days before the blisters develop.

As the virus multiplies it causes small painful, fluid-filled red spots, before the blisters appear. The blisters then burst and merge into a weeping sore, which gradually dries up and scabs over. Cold sores usually clear up within seven to 10 days and do not usually leave a scar. After the sore has healed, the virus lies dormant in the nerve again until the next attack is triggered. Recurrence can be common and depends on individual trigger factors.

Cold sores are usually mild and clear up without treatment. They can sometimes become infected with bacteria, especially if you touch or pick them with your hands. However, they can cause more serious problems in someone with a weakened immune system, such as after chemotherapy or due to HIV infection. These people may need treatment with antiviral tablets.

Very rarely, facial cold sores are caused by the herpes simplex type 2 virus, which is responsible for genital herpes.

See Your Pharmacist or Medical Professional

  • if the cold sore is in or near your eyes
  • if the cold sore is on your hands or in your genital area, or other parts of your body
  • if the cold sore is larger than a 10 cent piece
  • if you also have a fever and feel tired
  • if it is a child who is affected. Cold sores are not commonly seen in children, and it may be another condition such as impetigo
  • if there is pus, redness and swelling in or around the cold sore
  • if the cold sore has not healed after 14 days
  • if you suffer from cold sores frequently (e.g. more than 3 outbreaks per year)
  • if you have a weakened immune system
  • if you are unable to eat or drink because of the sore

Treatment Tips

  • treat the cold sore early; have treatment ready to use at the first tingle
  • wear a hat and use sunscreen on the affected area if you find the virus is reactivated by sun exposure
  • wash your hands before and after touching the cold sore, or applying cream to it
  • be especially careful to avoid spreading the cold sore to your eyes
  • avoid kissing or sharing towels, face flannels, toothbrushes, or eating and drinking utensils
  • do not share your cold sore cream with other people
  • do not pick the scab off; this may cause infection or scarring
  • if you are pregnant or breastfeeding not all products will be suitable; check with your pharmacist

Treatment Options

Antiviral products

[GENERAL SALE]
e.g. aciclovir (Blistex Antiviral Cold Sore Cream (New Formulation), Nyal Antiviral Cold Sore Cream, Zovirax Cold Sore Cream), povidone iodine (Betadine Cold Sore Ointment and Betadine Cold Sore Paint Pain Relief Formula (Lotion)), idoxuridine + lignocaine + benzalkonium chloride (Virasolve)

  • aciclovir-containing products are effective treatments for cold sores
  • they are proven to help speed healing and can prevent the cold sore from appearing if they are applied early enough
  • they should be used as soon as the first signs of a cold sore are noticed, such as a tingling sensation
  • they can be used at any stage to reduce healing time; see individual products for further details
  • products containing povidone iodine or idoxuridine may help treat cold sores but they are not as effective as aciclovir
  • products containing povidone iodine or benzalkonium chloride may help reduce the chances of a cold sore becoming infected with bacteria
  • if the cold sore is fully developed, products containing a local anaesthetic, such as lignocaine (Virasolve), can help relieve pain

[PHARMACY ONLY]

e.g. penciclovir cream (Vectavir)

  • applied every 2 hours during the daytime (at least 6 times a day) for 4 days
  • they are proven to help speed healing and can prevent the cold sore from appearing if they are applied early enough
  • they should be used as soon as the first signs of a cold sore are noticed, such as a tingling sensation
  • they can be used at any stage to reduce healing time

[PHARMACIST ONLY]

e.g. aciclovir and hydrocortisone (Zovirax Duo cream)

  • combination anti-viral and anti-inflammatory actions
  • should be used as soon as the first signs of a cold sore are noticed, such as a tingling sensation
  • can be used at any stage to reduce healing time
  • proven to help speed healing and can prevent the cold sore from appearing if they are applied early enough

e.g. famciclovir tablets (Ezovir, Elovax One Dose, Famvir for Cold Sores)

  • single dose of 3 tablets at once (1500mg) anti-viral
  • should be used as soon as the first signs of a cold sore are noticed, such as a tingling sensation (within 24 hours)
  • proven to help speed healing and can prevent the cold sore from appearing if they are applied early enough
  • generally well tolerated, may cause a headache, fatigue, nausea, or diarrhoea
  • only suitable for 18 years old and over

Pain relief products

[GENERAL SALE]
e.g. menthol and camphor (Nyal Cold Sore Cream)

  • products containing menthol and camphor can help reduce discomfort, but some people find that they irritate their skin

Other products

[GENERAL SALE] 

e.g. (bemotrizinol, avobenzone, isoamyl methoxycinnamate, oxybenzone, diethylamino hydroxybenzoyl hexyl benzoate) ViraproX lipbalm ointment

  • sunscreen SPF 30
  • specially designed for people who suffer from cold sores triggered from windy weather or sun exposure
  • a daily use lip balm containing sunscreen agents and moisturiser to help protect against cold sores
  • menthol to help reduce the discomfort of cold sores should a breakout occur.
  • apply every 30 minutes as needed

e.g. lysine, zinc, vitamin C (Blackmores Lyp-Sine)

  • vitamin supplement which may reduce number of outbreaks, severity and healing time of cold sores
  • can be used during an outbreak or ongoing

e.g. hydrocolloid patch (Compeed Total Care Invisible, Zovirax InvisiSeal)

  • promotes healing
  • reduces pain, redness, swelling, tingling, itching, burning
  • hides the cold sore and can be applied underneath makeup
  • prevents scabbing and crusting and reduces the risk of infection occurring

More Information

Availability of medicines

  • GENERAL SALE available through pharmacies and possibly other retail outlets.
  • PHARMACY ONLY available for sale through pharmacies only.
  • PHARMACIST ONLY may only be sold by a pharmacist.

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Last Reviewed: 14/07/2019

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References

1. Wolters Kluwer. Cold sores. UptoDate. 2019

2. Pharmaceutical Society of Australia. Australian Pharmaceutical Formulary. APF23

3. AusDI Medicines Information Database

4. MIMS Australia. MIMS Online. 2019