What is Cold sores?

Cold sores

What are cold sores?

Cold sores are blisters that appear on your lips and around your mouth. They are caused by a virus called the herpes simplex virus.

If you get cold sores, you were probably first infected with the

viruses
Viruses are microbes (tiny organisms) that need the cells of humans or other animals to exist. They use the machinery of cells to reproduce. Then they spread to other cells in the body.

virus when you were a child.

Source:
Baringer SR, Swoveland P.
Recovery of herpes simplex virus from human trigeminal ganglions.
New England Journal of Medicine. 1973; 288: 648-650.

¹ You may hear cold sores called herpes labialis or " fever blisters".

The virus that causes cold sores lives in the nerves in your face.

There are two types of herpes simplex virus: type 1 and type 2. Type 1 mostly causes cold sores.

Source:
British National Formulary.
Herpes simplex and varicella-zoster infection.
BNF 55. March 2008. Section 5.3.2.1. Available at http://bnf.org (accessed on 24 April 2008).

² Type 2 and type 1 can cause sores or

warts
Warts are small lumps that can grow on your skin. Warts are often caused by an infection with a kind of virus called a papillomavirus.

warts on the genitals. Here we are looking at what happens if you get type 1 virus on or around your mouth.

You can catch this virus from other people through their saliva. When you first get infected, you may or may not get symptoms.

Source:
Barabrash RA.
Update on treatment for oral herpes simplex viral infections (cold sores and fever blisters).
Today's Therapeutic Trends. 2001; 19: 39-57.

³ But children may have quite a serious illness when they get infected with the virus. They may get some or all of these symptoms:

Ulcers on their tongue, their lips and inside their mouth
Pain when swallowing
Fever
Swollen glands in their neck
Bad breath
Loss of appetite
Low energy
Feeling irritable.

If your child seems ill with these symptoms, you should take him or her to the doctor. He or she may need treatment.

Once you're infected, the virus stays in the nerves in your face. It can cause new cold sores at any time. There are certain things that seem to trigger new cold sores:

Throat infections
Tiredness
Stress
Your periods, if you are a woman
Sunlight
Drugs that affect your

immune system
The immune system is made up of the parts of the body that are devoted to fighting infection. The body is constantly being threatened by infections from things like bacteria, viruses and parasites. The immune system fights these infections in different ways. At the microscopic level, the immune system uses antibodies and white blood cells, which travel in the blood and target infectious agents, such as bacteria. These microscopic parts of the immune system either kill the infectious agent directly, or take it to other parts of the body, like the spleen, where it can be dealt with. The lymph nodes are another important part of the immune system. Within them, white blood cells filter through the foreign material that has entered the blood, to see if there are any infections. When you have a swollen gland during a cold, this is actually a lymph node that is reacting to the infection. Unfortunately, it is possible for the immune system to become confused and to use its destructive powers to target healthy parts of the body. Diseases that result from this type of situation are called autoimmune diseases.

immune system (such as

steroids
Steroids are a type of chemical. Your body naturally produces steroids, which play a part in many of its processes. For example, steroids are involved in how your immune system, reproductive system and metabolism work. Steroids can also be given as medicines and are used for a number of different conditions: including asthma, rheumatoid arthritis and eczema. Corticosteroids are not the same as the steroids used by some body builders and athletes. Those steroids are called 'anabolic steroids'.

steroids). Your immune system is the part of your body that protects you against infection.

If you get cold sores, you can pass the virus onto other people through your saliva.

Source:
Birek C.
Herpes virus-induced diseases: oral manifestations and current treatment options.
Journal of the Californian Dental Association. 2000; 28: 911-921.

⁴ You're most likely to pass on the virus when you have cold sores. To reduce the risk of passing on the virus, you should avoid kissing when you have cold sores and be careful not to share cups, cutlery or towels. Also, avoid oral sex when you have a cold sore, because the virus can sometimes cause blisters on the genitals.

Source:
Barabrash RA.
Update on treatment for oral herpes simplex viral infections (cold sores and fever blisters).
Today's Therapeutic Trends. 2001; 19: 39-57.

Sources for the information on this page:

Baringer SR, Swoveland P.Recovery of herpes simplex virus from human trigeminal ganglions.New England Journal of Medicine. 1973; 288: 648-650.

British National Formulary.Herpes simplex and varicella-zoster infection.BNF 55. March 2008. Section 5.3.2.1. Available at http://bnf.org (accessed on 24 April 2008).

Barabrash RA.Update on treatment for oral herpes simplex viral infections (cold sores and fever blisters).Today's Therapeutic Trends. 2001; 19: 39-57.

Birek C.Herpes virus-induced diseases: oral manifestations and current treatment options.Journal of the Californian Dental Association. 2000; 28: 911-921.

This information was last updated on May 07, 2008

This information is for educational use only, and is not a substitute for prompt professional medical advice. Readers should always consult a physician or other professional for advice and treatment.
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