Cold sores, or fever blisters, are small, blister-like lesions that form on the lips, chin, cheeks, or in the nostrils, as well as the gums or the roof of the mouth. They result from infection with a herpes simplex virus. Antiviral medications may help manage them.
Cold sores usually cause pain, a burning sensation, or itching before they burst and crust over. People sometimes call them fever blisters.
The most common cause of cold sores is the herpes simplex virus type 1 (HSV-1). Other times, these sores result from an infection with a different strain, called herpes simplex virus type 2 (HSV-2).
In the United States,
There is no way to cure or prevent these sores, but a person can take steps to reduce the frequency and duration of outbreaks.
The viral strains that cause cold sores, usually HSV-1 and less often HSV-2, are highly contagious and transmit easily during close contact, such as sexual contact.
After the virus enters the body, a person may have:
- flu-like symptoms
- sores in or around their mouth or in their nostrils
- sores around the genital area, in some cases
It is possible for oral herpes sores, or cold sores, to develop around the genitals if
A cold sore outbreak typically lasts
The virus does not leave the body, and though it remains inactive most of the time, it can periodically reactivate to cause cold sores.
Most people with oral herpes do not realize it until they experience cold sores or other symptoms. Some people have just one outbreak and no reoccurrence because the virus stays dormant.
Others may have
Some people with oral herpes have no symptoms, and others only experience them after the first exposure to the virus.
Still, at least 25% of people with oral herpes experience reoccurring outbreaks. In this case, cold sores often appear in the same locations each time.
Initial symptoms of an HSV-1 infection may appear 2–20 days after exposure to the virus and can include:
- lesions on the tongue, mouth, chin, cheeks, or in the nostrils
- mouth or tongue pain
- lip swelling
- difficulty swallowing
- a sore throat
- swollen lymph nodes
- a high body temperature
There may also be an infection of the mouth and gums, known as gingivostomatitis. This lasts for
Also, in adults, an infection of the throat and tonsils called pharyngotonsillitis may develop with the initial oral herpes infection.
A cold sore develops in several stages when it reoccurs.
- A tingling, itching, or burning sensation around the mouth often indicates the start of an outbreak.
- Painful, fluid-filled sores appear, usually around the mouth.
- The sores break and produce fluid.
- A yellow crust forms on the sores.
- The crust comes off, revealing pink skin that heals in 3–4 days.
Without treatment, most cold sores disappear within
People with reoccurring outbreaks can manage them at home by recognizing the signs and using medication.
However, consult a healthcare provider if:
- Symptoms are severe.
- A cold sore does not start to heal within 10 days.
- The gums swell.
- The person has a weakened immune system.
- Other symptoms are causing concern.
A doctor can usually diagnose the issue by considering the symptoms and making a visual examination, but in some cases — such as if the person has a weakened immune system — they may also order a blood test or take a sample of a sore’s fluid for testing.
Some factors that can weaken the immune system include HIV, medications following an organ transplant, some types of cancer, and some cancer treatment.
Most cold sore outbreaks resolve in
However, some over-the-counter or prescription medications can shorten an outbreak’s duration and reduce any discomfort or pain, though these do not remove the virus from the body.
In most cases, it is best to use treatments as soon as the first signs of an outbreak appear.
Over-the-counter antiviral creams can shorten the duration of an outbreak. Most creams, such as Zovirax and Soothelip, contain acyclovir or penciclovir.
A person should apply the cream to the affected area every
Oral antiviral medications
Some examples of
- valacyclovir (Valtrex)
- acyclovir (Zovirax)
- famciclovir (Famvir)
A doctor may prescribe one of these medications if a person has a weakened immune system or otherwise has regular outbreaks.
A person takes it
These medications can shorten the duration of an outbreak and may keep them from reoccurring.
Over-the-counter options contain an analgesic such as benzocaine or lidocaine. They do not speed the healing process, but they can reduce discomfort.
Some pain relief medications for cold sores include:
People should dab these ointments, creams, or gels onto the sores with a Q-tip, and it is important not to share these products.
If a person applies the medication with a finger instead, they should wash their hands before and after.
Some alternate options include medications such as ibuprofen (Advil) or acetaminophen (Tylenol).
Some people find that the following home care techniques relieve cold sore symptoms:
- applying cold, soaked tea bags to the area every hour
- dabbing the area with diluted geranium, lavender, or tea tree oil
- using petroleum jelly to keep the skin moist, preventing cracking
There is no scientific evidence that these remedies work or are safe.
Rarely, oral herpes can lead to complications, especially in people with weakened immune systems.
Possible complications include:
- dehydration, if pain from the sores makes drinking difficult
- herpetic whitlow, a painful infection that can occur through a cut on the skin and cause blisters, usually on the fingers
- herpetic keratoconjunctivitis, a secondary infection that can cause eye swelling and irritation, sores on the eyelids, and, without treatment, vision loss
- encephalitis, or swelling of the brain, which may occur if the infection spreads
Encephalitis can be life threatening.
When sores are present, try to:
- Avoid kissing and other skin-to-skin contact involving the affected area.
- Use a dental dam or condom during oral sex.
- Avoid sharing personal items, such as towels and lip balm.
- Follow correct handwashing techniques.
- Avoid touching areas where sores can develop, such as the eyes, mouth, nose, and genitals.
- If touching the sores is necessary, wash the hands with soap and warm water before and after.
Cold sores can be a painful and disruptive symptom of oral herpes.
Many people do not experience complications and can manage outbreaks at home with over-the-counter or prescription treatment.
Anyone with a weakened immune system should let a doctor know if they have cold sores or any other oral herpes symptoms.
Recognizing the early indications of an outbreak and using treatment right away can help. Without treatment, cold sores often disappear within