Marian Nicholson, Director of the Herpes Viruses Association & Shingles Support Society, helps you to unravel the recurrence of cold sores for patients; tackling the causes of an outbreak, treatment options, and how the virus can be kept at bay.

What Causes Cold Sores?

Cold sores, also known as fever blisters, are caused by a herpes simplex virus. There are two types, called type one and type two. Most facial cold sores are caused by type one. A World Health Organisation report estimates that two-thirds of the world’s population have caught cold sores by the age of 25. However, the majority of people who have been infected will never experience symptoms.

How are Cold Sores Caught?

Cold sores are usually caught by being kissed by someone who has cold sore virus on their mouth. In some cases, a cold sore may then appear within a few days. Symptoms normally clear up in a week or 10 days.

It’s possible to catch the virus and never have symptoms – or perhaps develop the first noticeable cold sore symptoms months or years later. This is known as a having a dormant infection.

A person with facial cold sores may infect a partner when performing oral sex if sufficient virus is present on the mouth at the time. This is now a common cause of genital herpes. The resulting genital infection will be type one.

The virus is sometimes caught in other areas, such as hands / fingers, if there is broken skin there at the time of contact with another person’s infection. A cold sore on the finger is called a whitlow.

Cold sores are only caught by direct skin contact, with the affected area, usually the lips. They are not caught through sharing cups, cutlery, towels, lipsticks, etc. (unless there is warm pus on the item). Medical experts are clear about this, although unreliable sources on the internet and elsewhere may make misleading statements. (1)

Do Cold Sores Cause an Illness?

Sometimes a first cold sore may be accompanied by ulcers inside the mouth and throat as well as, or instead of, sores on the lips. During this first infection, there may be fever, headache, swollen glands in the neck and other flu-like symptoms. Painkillers can help at this stage.

What are Cold Sores Like?

1. First, a small red patch appears

2. A blister or cluster of blisters develops

3. The blister bursts, leaving a raw area

4. The raw area begins to scab and heal

5. Scabs may crack when the lips move and this may delay healing. The individual should try to keep the skin moisturised – see suggestions later in the article

6. Picking at the scab will delay healing

7. Wash hands before and after applying cream

8. The sore will heal by itself without scarring, usually in about seven-to-10 days

Must a First Infection be Treated?

Treatment is optional. In a bad case, antiviral medication started as soon as symptoms appear may shorten the duration of the outbreak. Symptoms will heal with or without treatment.

Why do Cold Sores Sometimes Return?

The virus stays dormant in two nerve junctions, behind each ear, and symptoms may sometimes reappear, often at times of stress or poor general health.

Can Cold Sores Appear Anywhere Else?

This is unlikely as cold sores usually reappear in the same place; however, some people get them elsewhere on the face. A facial infection can’t cause symptoms on other parts of the body. Antibodies made by the immune system in response to the infection will normally prevent reinfection in different areas.

Are there Warning Signs Before a Cold Sore Appears?

There may be an itch, tingle or shooting pain on part of the lip at first. Repeat cold sores are usually much milder and shorter than the first ones.

What Causes a Recurrence?

Triggers vary from person-to-person. Common triggers are stress, tiredness, being run down, having a period, drinking too much alcohol, or ultra-violet light, from the sun or from sun-beds.

Self-Help Suggestions for how your Patients can Prevent Cold Sores

A healthy lifestyle can help to keep the immune system in good shape and make cold sores less likely. These are possible triggers:

• Lack of sleep

• Poor diet

• Exposure to bright sunlight / ultra-violet light, outdoors or when using sunbeds. A good quality sunblock, especially on the lips, is recommended

What Medicine Can Prevent Frequent Cold Sores?

Antiviral tablets may be prescribed. People with a high frequency of cold sore outbreaks should see a doctor. Antiviral tablets are a more effective way of treating and preventing cold sores than antiviral creams.

What Treatments are Available from Chemists’ Shops?

There are different types of creams:

1. Some creams contain anaesthetics (e.g. lidocaine five per cent, benzocaine, prilocaine or tetracaine) which will stop any soreness if a cold sore breaks through. A small trial found that lidocaine five per cent ointment prevented cold sore outbreaks in one-in-three people and shortened the outbreaks that did appear from five days to two days. (2) No prescription is needed and cold sores are an indication for lidocaine purchase from a registered pharmacy

2. Antiviral creams containing aciclovir are widely available. If used at the ‘tingle’ stage, they can shorten outbreaks by 12 per cent (from an average of seven days down to six ¼ days). (3) A newer antiviral cream, Fenestil, contains penciclovir one per cent, and has a similar benefit

Self-Help Tips that May be Worth Investigating

Some people with cold sores have found these ideas helpful – they are not medically tested:

• Cold damp teabags applied hourly: applying a well-wrapped ice pack to the area for up to 90 minutes at the tingle stage

• A cream containing lemon balm mint (melissa officinalis), such as Lomaherpan, has been shown to minimise outbreaks if used promptly. This plant contains molecules which prevent the virus from entering skin cells (4)

• Geranium oil, lavender oil, or diluted tea tree oil are claimed to soothe

• Vaseline (petroleum jelly) can help to keep the skin supple and prevent it from cracking and may prevent scabs from coming off before healing is complete

Can there be Medical Complications?

Medical attention is rarely necessary for straightforward cold sore infections but there can occasionally be complications.

In rare cases, a cold sore infection may recur in one eye (but not both at the same time). This will usually follow the initial infection, but may occur simultaneously. If one eye is tingling and sore or red, a GP or an optician can carry out a fluorescein stain test to see if the cause is herpes simplex virus. If it is, the patient may be referred to an eye specialist.

Patients with areas of broken skin (such as eczema) should be advised to be careful during their first infection as sores may spread over these areas. This is called eczema herpeticum. It is most likely to happen during a first infection, but can be caused by a recurrence.

Patients with weakened immune systems (e.g. those taking cancer treatment drugs, or those who have had an organ transplant) may need to be prescribed antiviral medication to prevent constant cold sores.

Neonates should not be exposed to cold sore virus – they should not be kissed by family members or friends with cold sores as their immune systems are too immature to cope with the infection. If their mother has had cold sores from before the pregnancy, the baby will have transplacental protection and mother’s virus is not likely to cause neonatal herpes. (5)



2. Jean Cassuto. Topical local anaesthetic and herpes simplex Lancet Jan 14, 1989   8629;100-101

3. Richards DM, Carmine AA, Brogden RN, Heel RC, Speight TM, Avery GS. Acyclovir. A review of its pharmacodynamic properties and therapeutic efficacy.  Drugs. 1983 Nov;26(5):378-438.DOI: 10.2165/00003495-198326050-00002

4. See below


4. List of References for Lemon Balm

1. Weiss RF. Herbal Medicine. Gothenburg, Sweden: Ab Arcanum, 1988, 31, 286

2. Auf’mkolk M, Ingbar JC, Kubota K, et al. Extracts and auto-oxidized constituents of certain plants inhibit the receptor-binding and the biological activity of Graves’ immunoglobulins. Endocrinol 1985;116:1687–93

3. Dressing H, Riemann D, Löw H, et al. Insomnia: Are valerian/balm combination of equal value to benzodiazepine? Therapiewoche 1992;42:726–36

4. Dressing H, Köhler S, Müller WE. Improvement of sleep quality with a high-dose valerian/lemon balm preparation: A placebo-controlled double-blind study. Psychopharmakotherapie 1996;6:32–40

5. Wöhlbling RH, Leonhardt K. Local therapy of herpes simplex with dried extract of Melissa officinalis. Phytomedicine 1994;1:25–31

6. Koytchev R, Allen RG, Dundarov S. Balm mint extract (Lo-701) for topical treatment of recurring Herpes labialis. Phytomed 1999;6:225–30

7. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 160–1

8. Boullata JI, McDonnell PJ, Oliva CD. Anaphylactic reaction to a dietary supplement containing willow bark. Ann Pharmacother 2003;37:832–5

9. Blumenthal M, Busse WR, Goldberg A, et al. (eds). The Complete Commission E Monographs: Therapeutic Guide to Herbal Medicines. Boston, MA: Integrative Medicine Communications, 1998, 230