Cold sores are small wounds or lesions similar to blisters that appear on the lips, chin, cheeks, inside the nostrils, gums or palate (the latter two less frequently).
Normally, they produce pain, a burning sensation or itching before they break and form a scab.
They are often referred to as febrile herpes . The most common cause is herpes simplex type 1 (HSV-1), but sometimes herpes simplex type 2 (HSV-2) can also cause them.
In the United States, between 50 and 80 percent of people suffer from oral herpes, which makes them susceptible to cold sores.
There is no way to cure or prevent cold sores, but there are some guidelines we can follow to reduce the frequency and duration.
Quick facts about cold sores
Here are some key points about cold sores. You can find more details in the main article.
- Cold sores are small blisters that develop on the lips or around the mouth.
- The viral strain of herpes simplex HSV-1 is usually the cause.
- Normally, they disappear after 7 or 10 days without treatment.
- The virus is quite contagious and can be transmitted through direct contact.
- After contracting the “cold sore virus”, it remains inactive for most of the time, but factors such as fatigue and wounds can activate it.
Blisters appear on the face and around the mouth
Herpes simplex virus (HSV) causes cold sores. HSV-1 and HSV-2 are very contagious, since they can be transmitted very easily by direct contact.
After entering the body, the virus remains inactive most of the time, but, if a factor activates the virus, cold sores can develop.
Some people may suffer only one outbreak and not suffer recurrences, while others may have two or three a year.
Some individuals can carry the virus without suffering outbreaks, as it remains inactive or asleep.
HSV-2 infection can occur due to oral sex with a person suffering from genital herpes.
Many people carry the herpes simplex virus, but do not experience the symptoms. They only discover that they are infected if a cold sore appears.
The first time a cold sore appears, as part of a primary infection, it can be serious.
After that, cold sores are considered a symptom of HSV-1 and 2. They are the only recurring sign that the virus is present in the body.
In most cases, herpes infections have no detectable signs or symptoms.
Severe symptoms usually affect young children, as they have not had enough time to create antibodies as a defense.
Symptoms may include:
- lesions, blisters or ulcers on the tongue and mouth;
- pain in the mouth or tongue;
- swelling of the lip;
- possible swallowing difficulties;
- Sore throat;
- Inflamed glands;
- high body temperature;
- nausea, or
Infections can also occur in the mouth and gum, which is known as gingivostomatitis. It lasts 1 or 2 weeks and does not appear again.
Pharyngotonsillitis, an infection in the throat and tonsils, may appear in the primary infection that affects adults.
The herpes simplex virus causes cold sores.
When cold sores are recurrent, they can develop in several phases:
- A burning, itching and tingling sensation around the mouth usually indicates the onset of an outbreak of cold sores. Then, fluid-filled sores usually appear on the edge of the lower lip, and the glands may begin to swell.
- The sores usually appear in the same place always. You will feel pain and irritation around cold sores.
- A yellow crust forms in the upper area of the sores and disappears to give way to pink skin that heals without leaving scars.
Most cold sores go away in a week or two.
Individuals who have already suffered outbreaks of cold sores will know how to recognize a recurrence easily.
If you suspect that you or your children may have a primary infection, especially if the sore has not healed in a week, you should see a doctor.
The doctor usually recognizes the signs and symptoms quite easily, but may request a blood test.
In some cases, the doctor may take a sample of fluid extracted from cold sores to detect the presence of the virus.
It is usually done only in patients with very weak immune systems, for example, people who have undergone chemotherapy, or who have HIV or AIDS.
Most outbreaks of cold sores disappear in 1 or 2 weeks without treatment.
Some antiviral medications and ointments may shorten the duration of the outbreak and relieve discomfort and pain.
Antiviral and over-the-counter creams for cold sores can shorten the duration of a recurrent infection. Most creams contain Aciclovir or Penciclovir, such as Zovirax and Soothelip.
They are only effective if they are applied as soon as symptoms and tingling appear, as it indicates the appearance of a cold sore.
The cream has to be applied 5 times a day for 4 or 5 days to get a better effect. It can eliminate the symptom, but not the virus. Creams cannot prevent future occurrences.
If you want to buy antiviral creams, you can find a wide variety of products online with thousands of positive opinions.
Antiviral and oral medications
Valacyclovir, acyclovir or famciclovir are antiviral and oral medications.
They can greatly shorten it or even stop an outbreak of cold sores, but only if they are applied when the first symptoms appear.
A patient suffering from severe outbreaks a year can take medications every day to prevent them.
Treatments to relieve discomfort
People with cold sores can use creams to treat dryness and irritation.
In the pharmacy you can find some over-the-counter creams without antivirals. For example, Bonjela, Blistex, or Cymex, which help reduce discomfort.
These treatments do not speed up the healing process, but may help if cold sores are dry, itchy or painful.
Creams should be applied to cold sores without rubbing and then wash your hands. In addition, creams should not be shared, since the virus can be transmitted.
Ibuprofen or Tylenol, which contain paracetamol, may help with pain. They are available in liquid format for younger patients.
Pregnant women with cold sores should talk about treatment options with their doctor.
Patients with weakened immune systems
Patients who have, for example, HIV or AIDS or who are undergoing chemotherapy treatments, may suffer complications, since their immune system is affected and weakened.
The infection could spread to other parts of the body, such as the eyes, and there is a high risk of inflammation in the brain, which is known as encephalitis.
These patients may be prescribed antiviral pills and need to see a specialist.
The treatment depends on the severity of the symptoms and the patient’s disease.
It is very unlikely that cold sores cause complications, except on rare occasions, such as in patients with weakened immune systems.
Possible complications include:
Dehydration : It is possible to suffer this complication if the pain in the mouth and throat causes the patient not to drink water.
Herpetic whitlow : Cold sores spread to other parts of the body, for example, the hands, which causes blisters on the fingers, usually due to a cut or rub on the skin.
Antiviral medications can treat this type of complication.
Herpetic keratoconjunctivitis : A secondary infection causes the eyes to swell and irritate, possibly with blisters on the eyelids. Normally, antiviral medications can help.
Without treatment, the cornea could become infected, which causes a possible loss of vision.
Encephalitis : If the virus spreads to the brain, it can become inflamed. It involves a serious risk of brain damage and possible death.
This situation is very rare. Antiviral medications are injected into the patient’s bloodstream and treatment is usually effective.
Spread prevention and arrest
If the patient has cold sores, he should:
- avoid kissing or touching other people;
- avoid sharing towels, lipsticks, lip balms, cutlery and style items;
- maintain good hand hygiene;
- avoid touching other parts of the body, especially susceptible areas, such as the genitals or eyes, or
- Wash your hands with soap and hot water immediately after touching the cold sores.
Translated by Carmen María González Morales
Reviewed by Brenda Carreras
Medically reviewed by Sarah Taylor, MD, FAAD
Written by Yvette Brazier