Herpes simplex virus is a common infection that typically appears in and around the mouth (oral herpes) or the genitals (genital herpes). Ulcers may cause pain but usually resolve within a few days or weeks.

Herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) are two common types of herpes. Traditionally, HSV-1 is associated with oral herpes, while HSV-2 is associated with genital herpes. However, HSV-1 is increasingly being identified in cases of genital herpes.

After a person contracts the infection and has their first outbreak of symptoms, the virus becomes latent, or dormant. It may cause recurrent outbreaks and more ulcers at a later time.

The World Health Organization (WHO) reports that as of 2016, HSV-1 affected about 3.7 billion people under age 50, and HSV-2 affected 491 million people ages 15–49 years.

In this article, we discuss what oral and genital herpes ulcers look like, the time it takes for them to heal, as well as treatment options and possible complications.

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HSV-1 is most commonly responsible for the development of oral herpes ulcers. Doctors may also refer to oral herpes as cold sores or fever blisters. While HSV-2 can also lead to oral herpes, it is less likely.

According to the Centers for Disease Control and Prevention (CDC), in 2015 about 48% of people ages 14–49 years were estimated to have antibodies for HSV-1. This means they had been exposed to the virus and were at risk of primary or recurrent herpes lesions.

Close contact with a person who has oral herpes, such as kissing or oral sex, can lead to infection. Sharing certain objects, such as lip balm and silverware, with a person who has oral herpes can also cause infection.

In some cases, people can contract the virus from a person with an asymptomatic infection. This is known as asymptomatic viral shedding.

What the ulcer looks like

Before an ulcer or blisters appears, a person may experience itching, burning, or a tingling sensation around the lips.

Within 48 hours of blister formation, the blisters break open, leading to the oozing of fluid and scab formation.

Accompanying symptoms of oral herpes can vary from person to person and may include:

Ulcers may occur inside the mouth as well.

The primary infection is more likely to cause systemic symptoms, such as fever, than recurrent infections.

How long does the ulcer persist?

An oral herpes outbreak may last for 2–3 weeks. The blisters can resolve on their own and are unlikely to leave scars, but other symptoms may require treatment.

A person with an oral herpes outbreak lasting longer than 15 days or ulcers that are not healing should seek advice from a medical professional.

Complications

HSV-1 rarely leads to complications or severe disease, but it can still happen. For example:

  • HSV-1 infection can lead to dehydration and secondary bacterial skin infections. Skin infections occur if the virus comes in contact with the skin.
  • Non-oral manifestations of HSV-1 infection can lead to:
    • herpetic keratoconjunctivitis, which can cause irritation, blurry vision, and redness
    • herpetic whitlow, which leads to the appearance of blisters on the fingers
    • meningitis, which is inflammation of the brain

Genital herpes is a sexually transmitted infection (STI). HSV-2 is a likely cause of genital herpes, but HSV-1 is becoming increasingly common in genital herpes infections.

Infection with HSV-2 is more likely among females than males.

According to a 2021 study, 572,000 new genital herpes infections occurred in the United States in 2018.

People can get genital herpes by having oral, vaginal, and anal sex with someone who has HSV. They may also be able to contract HSV from a partner who does not have a visible sore and is unaware of their infection.

Certain risk factors can increase the risk of contracting genital herpes, such as having multiple sexual partners or having sex without a condom or other barrier method.

Having a weakened immune system can increase the risk of severe HSV infection, including having worse or recurring lesions and more frequent outbreaks.

What does it look like?

Most people with genital herpes either have mild symptoms or no symptoms at all.

The symptoms of genital herpes infection, whether from HSV-1 or HSV-2, can vary greatly. A person may have no symptoms at all or more systemic infection.

Systemic infections can lead to fever, malaise, and painful genital ulcers.

The first symptom of genital herpes can be a tingling sensation in the genitals or pain in the legs, hips, genitals, or buttocks. Genital herpes appears as one or more blisters on or around the rectum, genitals, or mouth.

During the first outbreak, people may also experience flu-like symptoms.

The blisters then break open, forming painful sores that form scabs as they heal.

Accompanying symptoms may include:

  • burning when urinating
  • possible change in vaginal discharge
  • vulvar swelling
  • bleeding between menstrual cycles
  • fever
  • malaise
  • headache
  • lymphadenopathy, or swelling of lymph nodes

How long ulcer persists

The first outbreak of genital herpes is likely to heal within 2–6 weeks.

Subsequent outbreaks are milder, typically healing within 10 days or so.

Complications

The first outbreak of genital herpes may result in some complications, such as:

  • vaginal yeast infections
  • bladder problems that make urinating difficult
  • meningitis
  • bacterial superinfection

Complications are less likely to occur with future outbreaks.

Treatment may differ for both types of herpes.

Oral herpes

The treatment for most oral herpes infections is time. While topical agents are available, they are often unnecessary or may only modestly improve outcomes.

However, in some people, doctors may consider oral antivirals. For instance, when:

  • there is a severe primary infection
  • the person has a condition that compromises their immune system, such as HIV
  • the person is experiencing frequent recurrent infections

Oral antivirals may include acyclovir, famciclovir, or valacyclovir. These medications can help reduce symptoms and shorten the duration of infection.

Antivirals are effective if the treatment starts early, generally in the first 72 hours after initial symptoms appear. Pain-relieving medications, such as lidocaine, directly applied to the sore may help relieve severe pain.

Genital herpes

Topical treatments are not effective for genital herpes. Treatment for genital herpes during the first outbreak involves antiviral medications, such as valacyclovir, famciclovir, or acyclovir, as soon as symptoms appear.

Future outbreaks are typically less severe and might not need much treatment or long durations of medications.

A sitz bath or warm water bath might be useful for relieving pain.

People who have frequent outbreaks may benefit from taking daily antiviral medications to decrease outbreaks and viral shedding.

Below are some common questions and their answers about herpes ulcers.

What can be mistaken for a herpes ulcer?

Other lesions may look similar to the ulcers that occur with HSV.

Sometimes oral ulcers can be mistaken for:

  • canker sores
  • another infection
  • allergic reactions
  • bug bites
  • chapped lips
  • pimples

Genital ulcers can be mistaken for:

Where else can herpes ulcers occur?

While herpes mostly occurs around the mouth or genitals, it can appear anywhere in the body.

For example, HSV-1 infection can occur in the eyes or fingers. HSV-1 and HSV-2 ulcers can appear on the buttocks, thighs, around the anus, and the hips.

What to do when herpes ulcers are not healing?

In most cases, herpes ulcers can heal by themselves. When they do not, antiviral medications can be extremely effective for oral and genital herpes.

However, if someone is concerned about their ulcer not healing, they must consult a doctor who can better advise on the next steps.

Herpes ulcers typically occur as fluid-filled blisters that can appear around the mouth and genitals.

HSV-1 is more commonly associated with oral herpes, whereas HSV-2 is more closely associated with genital herpes, although HSV-1 can also cause it.

Usually, close contact with a person who has an HSV can cause oral or genital herpes to develop.

Eventually, the blisters break open, resulting in painful sores that scab over time. For some, it may take a few weeks for oral and genital herpes to heal.

Antiviral medications are available for oral and genital herpes. People experiencing severe symptoms that last longer than a couple weeks should seek advice from a doctor.