What are cold sores?
Cold sores appear on the face and around the mouth.
They usually cause pain, a burning sensation, or itching before they burst and crust over.
In the United States (U.S.), between 50 and 80 percent of people have oral herpes, making them potentially susceptible to cold sores.
There is no way to cure or prevent cold sores, but steps can be taken to reduce their frequency and duration.
Fast facts on cold sores
Here are some key points about cold sores. More detail is in the main article.
- Cold sores are tiny blisters that develop on the lips or around the mouth.
- The herpes simplex virus strain HSV-1 normally causes them.
- They usually clear within 7 to 10 days without treatment.
- The virus is highly contagious and can be passed on through close direct contact.
- After someone has contracted the "cold sore virus", it remains inactive for most of the time, but triggers such as fatigue and injury can activate it.
The herpes simplex virus (HSV) causes cold sores. HSV-1 and HSV-2 are highly contagious viruses that can be transmitted easily as a result of close contact.
After entering the body, the virus remains inactive most of the time, but, if a trigger activates the virus, a cold sore can develop.
One person may have just one outbreak and no recurrence, while others may have two or three outbreaks each year.
Some people may carry the virus and never have an outbreak because it remains dormant.
Infection with HSV-2 may result from oral sex acts with a person who has genital herpes.
Signs and symptoms
Many people have the herpes simplex virus but no symptoms. They will only know they are infected if cold sores appear.
The first time a cold sore appears, as part of a primary infection, it may be severe.
After this, cold sores are considered a symptom of HSV-1 and 2. They remain as the only recurring sign that the virus is present in the body.
In most cases, there are no other detectable signs or symptoms of a herpes infection.
Severe symptoms are more likely to affect young children, as they have not yet had time to build up antibodies as a defense.
Symptoms can include:
- lesions, blisters, or ulcers on the tongue or mouth
- mouth or tongue pain
- lip swelling
- possible swallowing difficulties
- sore throat
- swollen glands
- high body temperature
There may also be an infection of the mouth and gums, known as gingivostomatitis. This lasts for 1 to 2 weeks, and it does not recur.
Pharyngotonsillitis, an infection of the throat and tonsils, may occur when the primary infection affects adults.
Stages of a cold sore
The herpes simplex virus causes cold sores.
A cold sore will develop in several stages when it recurs.
- A tingling, itching or burning sensation around the mouth often indicates the start of a cold-sore outbreak. Fluid-filled sores, often on the edges of the lower lip, tend to follow this. Glands may start to swell.
- The sores often appear in the same place each time. Pain and irritation develop alongside the cold sore.
- The sores break and ooze.
- A yellow crust forms on top of the sores and scabs off to uncover pink skin that heals without scarring.
Most cold sores disappear within a week or two.
Those with previous experience of a cold sore outbreak will easily recognize a recurrence.
People who suspect that they or their child may have a primary infection, especially if the sore has not healed within a week or so, should see their doctor.
The signs and symptoms are usually clear enough for a doctor to make a diagnosis, but they may also order a blood test.
In some cases, the doctor may take a sample of the fluid scraped from the cold sore to detect the presence of the virus.
Most cold sore outbreaks clear up within 1 to 2 weeks without treatment.
Some ointments and antiviral medications may shorten the outbreak's duration and alleviate discomfort and pain.
Over-the-counter (OTC) cold sore antiviral creams can shorten the duration of a recurrent infection. Most creams contain either acyclovir or penciclovir, such as Zovirax and Soothelip.
They are only effective if applied as soon as symptoms appear and tingling suggests the onset of a cold sore.
The cream needs to be applied up to five times daily for 4 to 5 days for best effect. This can eliminate the symptoms but not the virus. Creams cannot prevent future occurrences.
Oral Antiviral medications
Valacyclovir, acyclovir, or famciclovir are oral antiviral medications.
They can significantly shorten or even stop a cold sore outbreak if taken when the first signs appear.
A patient who has several outbreaks a year make take these every day to prevent outbreaks.
Treatments to relieve discomfort
People with cold sores can use creams to treat the dryness and irritation.
Some OTC creams are available that do not contain antiviral medication. Examples are Bonjela, Blistex, or Cymex. These may reduce discomfort.
These treatments do not speed up the healing process, but they may help if the cold sores are dry, itchy, or painful.
People should dab these creams onto the sores without rubbing, then wash their hands. People with cold sores should not share creams.
Ibuprofen or Tylenol, containing paracetamol, may help alleviate pain. These are available in liquid form for younger patients.
Pregnant women who have cold sores should discuss their treatment options with their doctor.
Patients with weakened immune systems
Patients who have, for example, HIV or AIDS or who are undergoing chemotherapy, may face complications, because their immune system is compromised.
Such patients may be prescribed antiviral tablets. They may need to see a specialist.
Treatment depends on the severity of symptoms, and the patient's medical condition.
Cold sores are unlikely to cause complications, except occasionally, in patients with a weakened immune system.
Possible complications include:
Dehydration: This is possible if pain in the mouth and throat makes the patient reluctant to drink.
Herpetic whitlow: The cold sore virus spreads to other parts of the body, for example, the hands, causing blisters to appear on their fingers, usually through a cut or graze in the skin.
Antiviral medications can treat this type of complication.
Herpetic keratoconjunctivitis: A secondary infection causes the eyes to become swollen and irritated, possibly with sores on the eyelids. Antiviral medication can usually help.
Without treatment, the cornea may become infected, resulting in possible vision loss.
Encephalitis: If the virus spreads to the brain, the brain can swell. There is a serious risk of brain damage, and possibly death.
This is extremely rare. Antiviral medications are injected straight into the patient's bloodstream. Treatment is usually effective.
Prevention and stemming the spread
When sores are present, the individual should:
- Avoid kissing or skin contact with other people
- Avoid sharing towels, lipstick, lip balm, cutlery, and so on with others.
- Follow good hand hygiene
- Avoid touching other parts of the body, especially susceptible areas, such as the genitals and eyes
- If you touch the sores immediately wash the hands with soap and warm water