Herpes on the Tongue, Throat or Roof of the Mouth

Most people picture a cold sore as a blister on the lip. But herpes can also show up inside the mouth, on the tongue, gums, roof of the mouth or throat, and those sores are easy to confuse with other mouth sores. This guide covers what oral herpes can look like in each spot, how it differs from a canker sore, and when to get checked.

Can herpes cause sores on the tongue, gums or roof of the mouth?

Yes. Oral herpes is an infection of the lips, mouth or gums caused by the herpes simplex virus, usually type 1 (HSV-1). It causes small, painful blisters, and MedlinePlus lists the gums, lips, mouth and throat as places they can form.

Where the sores appear depends partly on the type of infection:

• Cold sores usually occur outside the mouth, on or around the lips. When they are inside the mouth, they are usually on the gums or the roof of the mouth.
• A first infection can affect more of the mouth. MedlinePlus lists blisters, often on the tongue, cheeks, roof of the mouth and gums. After the blisters pop they form ulcers, often on the tongue or cheeks.

Sores can look like other mouth sores, so looks alone can’t confirm herpes. The NHS also notes that cold sores can appear as a small group of pinhead-sized ulcers inside the mouth.

Is it a canker sore or a cold sore?

This is the question behind most searches like this one.

• Canker sores are small, round sores in the mouth, such as on the inside of the cheek, under the tongue or in the back of the throat. They usually have a red edge and a gray center. They are not the same as cold sores, and they aren’t contagious.
• Cold sores are caused by herpes simplex. They begin as blisters, often after tenderness, tingling or burning, and then crust over. The virus is most contagious while sores are present.

The NHS says mouth ulcers can also appear on the tongue and are not contagious. Looks can overlap, so if you’re unsure, a swab of a fresh sore is the way to settle it.

What is herpetic gingivostomatitis?

This is the name for a first herpes infection of the mouth, also called primary herpetic gingivostomatitis or herpetic stomatitis. MedlinePlus describes it as a viral infection of the mouth that causes sores and ulcers, and says young children commonly get it when first exposed to the virus. The first outbreak is usually the most severe.

Symptoms can include:

• Blisters and ulcers on the tongue, cheeks, roof of the mouth and gums
• Swollen gums
• Mouth pain, and difficulty swallowing or drooling
• Fever, which may come 1 to 2 days before the blisters
• Irritability in young children

MedlinePlus says a child should recover completely within 10 days without treatment. Later outbreaks are usually milder, most often a cold sore on the mouth. The NHS advises seeing a doctor if you or your child also have swollen, painful gums and sores in the mouth.

Can herpes cause a sore throat?

It can. A sore throat is one of the listed symptoms of oral herpes during a first infection, along with fever, headache and swollen lymph nodes. MedlinePlus lists a sore throat, fever, swollen glands and painful swallowing as symptoms that can come before the blisters. See a clinician if your sore throat is severe, comes with mouth sores, or does not get better.

What does an oral herpes outbreak look like?

Symptoms often begin with tingling, itching or burning near where the sores will appear. Blisters or ulcers then form, and they are typically painful. Blisters may break open, ooze and crust over.

Later outbreaks are usually shorter and less severe than the first. Some people notice that illness, fever, sun exposure, a period or stress comes before an outbreak, while others see no clear trigger.

How is oral herpes tested?

For an active sore, a swab for herpes (PCR) is the most sensitive test. A clinician swabs a fresh sore. If a sore has already healed, a swab may not find the virus, and that does not mean the virus is absent.

A blood test for type-specific antibodies (IgG) can show whether you have been infected with HSV-1 or HSV-2 at some point. It doesn’t show whether a particular sore is herpes. It can miss a recent infection, so repeat testing about 12 weeks after a possible exposure may be needed. The CDC does not recommend routine HSV-2 blood screening for the general population, so think about whether it would help you before you order one.

What helps while it heals?

Antiviral medicine prescribed by a clinician can shorten outbreaks and make them less frequent for some people. Whether it suits you is a decision to make with a clinician who knows your health history.

For comfort, WHO notes that cold drinks or popsicles can help with oral herpes symptoms, and over-the-counter pain medicines can ease discomfort. MedlinePlus also suggests avoiding hot drinks, spicy and salty foods and citrus. Ask a pharmacist before using any product, especially if you are pregnant.

Until the sore has healed, avoid oral contact with others, including oral sex, and don’t share objects that have touched saliva. Herpes can also spread when no symptoms are visible, so the risk doesn’t end when a sore looks better.