St. Luke's Hospital
Located in Chesterfield, MO
Main Number: 314-434-1500
Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
Find a Physician Payment Options Locations & Directions
Follow us on: facebook twitter Mobile Email Page Email Page Print Page Print Page Increase Font Size Decrease Font Size Font Size
Meet the Doctor
Spirit of Women
Community Health Needs Assessment
Home > Health Information

Multimedia Encyclopedia


    Herpes - oral

    Cold sore; Fever blister; Oral herpes simplex; Herpes labialis; Herpes simplex

    Oral herpes is an infection of the lips, mouth, or gums due to the herpes simplex virus. It causes small, painful blisters commonly called cold sores or fever blisters. Oral herpes is also calledherpes labialis.


    Oral herpes is a common infection of the mouth area. It is caused by theherpes simplex virus type 1 (HSV-1). Most people in the United States are infected with this virus by age 20.

    After the first infection, the virus goes to sleep (becomes dormant) in the nerve tissues in the face. Sometimes, the virus later "wakes up" (reactivates), causing cold sores.

    Herpes virus type 2 (HSV-2) usually causes genital herpes. However, sometimes HSV-2 is spread to the mouth during oral sex, causing oral herpes.

    Herpes viruses spread easily. You can catch this virus if you:

    • Have intimate or personal contact with someone who is infected
    • Touch something that is infected with the herpes virus, such as infected razors, towels, dishes, and other shareditems

    Parents may spread the virus to their children during regular daily activities.


    Some people get mouth ulcers when they first come into contact with HSV-1 virus. Others have no symptoms. Symptoms usually occur in kidsbetween 1 and 5 years old.

    Symptoms may be mild or severe.

    They usually appear within 1-3 weeks after you come into contact with the virus. They may last up to 3 weeks.

    Warning symptoms include:

    • Itching of the lips or skin around mouth
    • Burning near the lips or mouth area
    • Tingling near the lips or mouth area

    Before blisters appear, you may have:

    • Sore throat
    • Fever
    • Swollen glands
    • Painful swallowing

    Blisters or a rash may form on your:

    • Gums
    • Lips
    • Mouth
    • Throat

    Many blisters are called an "outbreak." You may have:

    • Red blisters that break open and leak
    • Small blisters filled with clear yellowish fluid
    • Several smaller blisters may grow together into a large blister
    • As the blister heals, it gets yellow and crusty, eventually turning into pink skin

    Symptoms may be triggered by:

    • Menstruation or hormone changes
    • Being out in the sun
    • Fever
    • Stress

    If the symptoms return later, they are usually more mild.

    Exams and Tests

    Your doctor or nurse can diagnose oral herpes by looking at your mouth area. Sometimes, a sample of the sore is taken and sent to a laboratory for closer examination. Tests may include:

    • Viral culture
    • Viral DNA test
    • Tzanck test to check for HSV


    Symptoms may go away on their own without treatment in 1 to 2 weeks.

    Yourhealth care provider can prescribe medicines tofight the virus. This is called antiviral medicine. It can helpreduce pain and make your symptoms go away sooner. Medicines used to treat mouth sores include:

    • Acyclovir
    • Famciclovir
    • Valacyclovir

    These medicineswork best if you take them when you have warning signs of a mouth sore, before any blisters develop. If you get mouth sores frequently, you may need to take these medicines all the time.

    Antiviral skin creams may also be used. However, they are expensive andoften only shorten the outbreak by a few hours to a day.

    The following steps can also help make you feel better:

    • Apply ice or a warm washcloth to the sores to help ease pain.
    • Wash the blister gently with germ-fighting (antiseptic) soap and water. This helps prevent spreading the virus to other body areas.
    • Avoid hot beverages, spicy and salty foods, and citrus.
    • Gargle with cool water or eat popsicles.
    • Rinse with salt water.
    • Take a pain reliever such as acetaminophen (Tylenol).

    Outlook (Prognosis)

    Oral herpes usually goes away by itself in 1 to 2 weeks. However, itmay come back.

    Herpes infection may be severe and dangerous if:

    • Itoccurs in or near the eye
    • You have a weakened immune system due to certain diseases and medications

    Possible Complications

    Herpes infection of the eye is a leading cause of blindness in the United States. It causesscarring of the cornea.

    Other complications of oral herpes may include:

    • Return of mouth sores and blisters
    • Spread of the virus to other skin areas
    • Bacterial skin infection
    • Widespread body infection, which may be life threatening in people who have a weakened immune system due toatopic dermatitis, cancer, or HIV infection

    When to Contact a Medical Professional

    Call for an appointment with your health care provider if you have :

    • Symptoms that are severe or that don't go away after 2 weeks
    • Sores or blisters near your eyes
    • Herpes symptoms and a weakened immune system due to certain diseases or medicines


    Here are some tips to prevent mouth sores:

    • Applysunblock or lip balm containing zinc oxide to your lips before you go outside.
    • A moisturizing balm to prevent the lips from becoming too dry may also help.
    • Avoid direct contact with herpes sores.
    • Wash items such as towels and linens in boiling hot water after each use.
    • Do not share utensils, straws, glasses, or other items if someone has oral herpes.

    Do not have oral sex if you have oral herpes, especially if you have blisters. You can spread the virus to the genitals. Both oral and genital herpes viruses can sometimes be spread even when you do not have mouth sores or blisters.


    Habif TP. Warts, herpes simplex, and other viral infections. In: Habif TP, ed. Clinical Dermatology. 5th ed. Philadelphia, Pa: Mosby Elsevier; 2009: chap 12.

    Whitley RJ. Herpes simplex virus infections. In: Goldman L, Schafer AI, eds. Cecil Medicine. 24th ed. Philadelphia, Pa: Saunders Elsevier; 2011:chap 382.


    • Herpes simplex - close-u...


      • Herpes simplex - close-u...


      A Closer Look

        Self Care

        Tests for Herpes - oral

        Review Date: 10/14/2012

        Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, Stephanie Slon, and Nissi Wang.

        The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

        A.D.A.M. content is best viewed in IE9 or above, Fire Fox and chrome browser.

        Back  |  Top
        About Us
        Contact Us
        Locations & Directions
        Quality Reports
        Annual Reports
        Honors & Awards
        Community Health Needs

        Brain & Spine
        Sleep Medicine
        Urgent Care
        Women's Services
        All Services
        Patients & Visitors
        Locations & Directions
        Find a Physician
        Tour St. Luke's
        Patient & Visitor Information
        Contact Us
        Payment Options
        Financial Assistance
        Send a Card
        Mammogram Appointments
        Health Tools
        My Personal Health
        Spirit of Women
        Health Information & Tools
        Clinical Trials
        Employer Programs -
        Passport to Wellness

        Classes & Events
        Classes & Events
        Spirit of Women
        Donate & Volunteer
        Giving Opportunities
        Physicians & Employees
        For Physicians
        Remote Access
        Medical Residency Information
        Pharmacy Residency Information
        Physician CPOE Training
        St. Luke's Hospital - 232 South Woods Mill Road - Chesterfield, MO 63017 Main Number: 314-434-1500 Emergency Dept: 314-205-6990 Patient Billing: 888-924-9200
        Copyright © St. Luke's Hospital Website Terms and Conditions  |  Privacy Policy  |  Notice of Privacy Practices PDF  |  Patient Rights PDF Sitemap St. Luke's Mobile