Oral Herpes: Causes, Treatments, and Prevention

By Alicia Wooldridge, MD
Medically reviewed checkmarkMedically reviewed
August 24, 2022

Whether you know it or not, chances are either you or someone you know has oral herpes. Often referred to as cold sores or fever blisters, oral herpes is most often caused by herpes simplex virus 1, and, worldwide, 67% of people under age 50 have HSV-1.

However, there’s much confusion about oral herpes, particularly how it’s related to genital herpes.This article will explain everything you need to know about oral herpes, starting with the symptoms and causes.

Then I’ll discuss the treatment, prevention, and precautions of cold sores. Lastly, I’ll wrap up with when to see a doctor about mouth sores.

Oral Herpes Symptoms

Most of the time oral herpes is asymptomatic, but when outbreaks occur, it can be painful.

Symptoms typically progress through the following stages:

  • Itching, tingling, or burning of the skin around the lips and mouth (typically occurs 1-3 weeks after exposure to the virus and 1-2 days before painful sores appear)
  • Cold sores begin to appear around the lips, mouth, throat, and gums
  • The blisters burst and ooze a clear or yellowish fluid
  • The open sores begin to heal and crust over
  • The scabs fall off, leaving pink skin that does not typically scar

The first outbreak tends to be the worst, causing more intense symptoms that may also include:

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Causes of Oral Herpes

Oral herpes is most often caused by herpes simplex virus type 1 (HSV-1). It can also be caused by herpes simplex virus type 2 (HSV-2)—which most often causes genital herpes—but this is less common.

Both forms of HSV are extremely contagious and can be passed to others through saliva or direct contact.

If you have the herpes virus, the following things can trigger an outbreak:

How common is oral herpes?

About 3.7 billion people worldwide who are younger than 50 have oral herpes. Most people acquire HSV-1 through non-sexual contact with saliva (such as being kissed or touched or sharing objects) during childhood or young adulthood.

How it spreads

Oral herpes typically spreads when someone infected with HSV-1 shares saliva or comes in close contact with another person.

That means kissing, oral sex, and sharing objects (like utensils, makeup, and towels) with an infected person can spread the virus.

Oral herpes is most contagious during outbreaks (when fever blisters are visible), but it’s possible to spread it at any time. This is because the skin can shed the virus even when no herpes sores are present. 

Less commonly, herpes simplex virus 2 (HSV-2) can cause oral herpes. This happens when someone performs oral sex on a partner who has genital herpes, and the HSV-2 virus spreads from their partner’s genitals to their mouth area.

Similarly, it’s possible to give someone genital herpes by infecting them with HSV-1. This occurs when someone with oral herpes performs oral sex and spreads the virus from their mouth area to their partner’s genital area.

For this reason, it’s important not to give or receive oral sex if you are experiencing an oral or genital herpes outbreak.

Treatment and Management of Oral HSV

Although oral herpes is an incurable, lifelong disease, it can be managed. Treatment options include:

Over-the-counter medication: The OTC cream docosanol (Abreva) may shorten the duration of a cold sore or prevent one from forming if used at the first signs of an outbreak. Oral pain relievers can also help with discomfort.

 Prescription medication: If over-the-counter medications aren’t enough or you experience recurrent outbreaks, your doctor may prescribe antiviral medication such as acyclovir (Zovirax), valacyclovir (Valtrex), famciclovir, or penciclovir (Denavir). These medications are most effective if started within 24-48 hours of symptom onset. If these still don’t help, IV antiviral medication may be necessary.

Home remedies: Applying a clean, cold compress to cold sores may help reduce pain and promote healing. Also wear lip balm with SPF to protect the outbreak from sunburn.

Prevention and Precautions of Oral HSV

Although oral herpes is highly contagious, you can take steps to prevent infection or, if you have been diagnosed, prevent an outbreak.

To avoid being infected with oral herpes:

  • Avoid intimate contact (including kissing, oral sex, and close touching) with anyone who has visible oral herpes
  • Wash your hands thoroughly before touching your mouth, eyes, or genitals if you have been around someone who has visible oral herpes
  • Avoid sharing items like utensils, towels, and lipstick with anyone who has visible oral herpes 

If you’ve been diagnosed with oral herpes, take the following precautions to lessen the chance of triggering a recurrent outbreak:

  • Do your best to manage stress
  • Keep your lips moisturized with lip balm
  • Maintain a healthy lifestyle to reduce the risk of colds

Complications of oral herpes

People with weakened immune systems (due to infections such as HIV) are at greater risk of complications if they contract oral herpes.

These complications include:

Herpes keratitis: This viral eye infection can occur if you touch your eye after touching a cold sore. Severe infections can be very painful and even lead to blindness. 

Eczema herpeticum: People who have eczema and contract the herpes virus can develop this serious infection. Symptoms include a painful rash that looks somewhat like chicken pox. It is most common in young children and infants who have moderate or severe eczema and can be life-threatening.

Herpes simplex encephalitis: This rare, life-threatening disorder leads to swelling of the lining of the brain.

Neonatal herpes: Children younger than six months old who become infected with herpes are diagnosed with neonatal herpes, a potentially life-threatening version of the condition. The herpes virus is more serious in newborns because their immune systems are not fully developed, and they can experience severe fevers and seizures.  

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When to See a Doctor

If you think you may be experiencing oral herpes for the first time, make an appointment with your doctor as soon as possible. Not only can they properly diagnose you, they can also share tips and, if necessary, prescribe medication to manage your cold sores.

If you have been diagnosed with oral herpes, see a healthcare provider if you have an outbreak and:

  • Your symptoms are extremely severe
  • Your symptoms don’t go away after two weeks
  • You have sores near your eyes
  • Your immune system is weakened due to illness or medication

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Frequently Asked Questions

Is oral herpes a STD?
Oral herpes is not always transmitted through sexual contact, although it can be. It is possible to become infected with oral herpes when giving oral sex to someone who has genital herpes, but it is more common to contract oral herpes through saliva (such as kissing) or other direct contact.
What does oral herpes look like?
An oral herpes outbreak looks like one or more sores on or around the lips. These sores look like red blisters filled with fluid. Over time, these blisters break and ooze before scabbing over and healing.
How long is oral herpes contagious?
There is no cure for oral herpes, and it is a lifelong disease. That means you can spread the virus at any time. However, you are most contagious during an outbreak (when cold sores are visible), and outbreaks typically take a couple of weeks to completely heal.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Alicia Wooldridge, MD

Dr. Alicia Wooldridge is a board certified Family Medicine physician with over a decade of experience.