Skip to main content

Oral Herpes Simplex Virus Infections

Medically reviewed by Last updated on Jun 6, 2022.

What are oral herpes simplex virus infections?

Oral herpes simplex virus (HSV) infections cause sores to form on the mouth, lips, or gums. HSV has 2 types. Oral HSV infections are most often caused by HSV type 1. HSV type 2 normally affects the genital area, but may also occur in the mouth. After you are infected, the virus hides in your nerves and may return. An HSV infection that comes back is also known as a cold sore.

What causes oral herpes simplex virus infections?

Oral HSV infections are easily spread through close, personal contact with someone who has HSV. The infection may be spread when you touch the blisters and then touch your eyes, mouth, nose, or a cut. The infection can also spread through a kiss or on a shared eating utensil. Oral HSV infections that come back may be triggered by stress, trauma, or exposure to temperature extremes. They may also be triggered by anything that weakens your immune system, such as a cold or the flu.

What are the signs and symptoms of oral herpes simplex virus infections?

Signs and symptoms of oral HSV infections usually develop suddenly and heal without treatment in about 10 days. Sores are usually filled with a yellow-white fluid and may break easily. Sores may join together to form larger open sores. You may also have the following:

  • Burning, tingling, itching, or pain at the affected area before sores form
  • Blisters or painful small, round, shallow ulcers on the lips, mouth, or gums
  • Fever, chills, headache, and enlarged lymph nodes in the neck
  • Getting tired and irritated easily and more than normal for you
  • Loss of appetite or not wanting to eat or drink
  • Red, swollen, bleeding gums, or sore throat

How are oral herpes simplex virus infections diagnosed?

Your healthcare provider will examine you and carefully look at your blisters. He may ask if you have other medical conditions. He will also need to know when the sores started, along with your other symptoms. You may also need any of the following:

  • Fluid sample: A sample is taken from the affected area and checked under the microscope or sent for other testing.
  • Blood tests: Your blood is tested for antibodies and to see if you have been exposed to HSV. The tests may also show if you have developed antibodies from exposure to HSV.
  • Biopsy: This is a procedure used to remove a small piece of tissue from the ulcer. This sample is then sent to the lab for tests.

How are oral herpes simplex virus infections treated?

HSV infection sores normally heal on their own without scarring. You may need any of the following to help manage symptoms:

  • Antiviral medicine: This decreases symptoms and shortens the amount of time blisters are present. You may also need to take it daily to prevent blisters. The medicine may be given as a liquid, , pill, or ointment. Use as directed.
  • Numbing medicine: This decreases mouth pain. It is usually given as a mouth rinse. Use it before you eat or drink, or as directed.

How can I manage my symptoms?

  • Eat soft, bland foods: Avoid salty, acidic, spicy, sharp-edged, and hard foods. Eat healthy foods to help healing.
  • Drink liquids: Cool liquids may help soothe your mouth and numb the pain. Avoid citrus or carbonated drinks, such as orange or grapefruit juice, lemonade, or soda. These liquids may cause your mouth to hurt more. A straw may help if you have blisters on the lips or tongue.
  • Use ice: Ice helps decrease swelling and pain. Drink cold water or suck on ice to help decrease pain on your tongue or inside your mouth. Use an ice pack, or put crushed ice in a plastic bag on your lip. Cover it with a towel and place it on your lip for 15 to 20 minutes every hour or as directed.

What are the risks of oral herpes simplex virus infection?

If left untreated, an oral HSV infection may make it difficult to eat or drink because of the pain. The infection may spread to other parts of your body or to other people. The infection can return and affect other areas, such as your brain.

How can I prevent the spread of the herpes simplex virus?

  • Do not have close contact with people until the blisters heal. This includes touching, kissing, and oral sex.
  • Do not get close to babies or to people who are sick while you have cold sores.
  • Do not share eating utensils, towels, lip balm, or makeup with another person.
  • Do not touch the blisters or pick at the scabs. Do not touch other body parts, especially your eyes or genitals without washing your hands first. Wash your hands often.

When should I contact my healthcare provider?

  • You have a fever.
  • Your symptoms become worse or do not improve a week after you start treatment.
  • You have difficulty eating or drinking because of the pain in your mouth.
  • You get a headache, are nauseated, or vomit.
  • Your eyes feel irritated or you feel like you have something in your eye.
  • Your skin becomes itchy, swollen, or develops a rash after you take your medicine.
  • You have questions or concerns about your condition or care.

When should I seek immediate care?

  • You get a fever, feel achy, or see pus instead of clear fluid in the sores.
  • You get sores on your eyes.
  • You have abdominal pain, a severe headache, or confusion.
  • You get new symptoms, or old symptoms return after you have been treated.

Care Agreement

You have the right to help plan your care. Learn about your health condition and how it may be treated. Discuss treatment options with your healthcare providers to decide what care you want to receive. You always have the right to refuse treatment. The above information is an educational aid only. It is not intended as medical advice for individual conditions or treatments. Talk to your doctor, nurse or pharmacist before following any medical regimen to see if it is safe and effective for you.

© Copyright IBM Corporation 2022 Information is for End User's use only and may not be sold, redistributed or otherwise used for commercial purposes. All illustrations and images included in CareNotes® are the copyrighted property of A.D.A.M., Inc. or IBM Watson Health

Learn more about Oral Herpes Simplex Virus Infections

Treatment options

Care guides

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.