Having a cold sore is no fun. These painful sores, also called fever blisters, usually appear around the mouth. They cause itching and burning and can look unattractive.
Cold sores usually aren’t a serious health problem. In healthy people, they clear up in a couple of weeks.
Discover what causes cold sores, as well as the best cold sore treatments.
What Causes Cold Sores?
How do people get cold sores?
People get cold sores by kissing or touching someone with a cold sore. The virus that causes cold sores is very contagious. Many people get it in early childhood.
The virus travels through the nerves and stays in the body even after the cold sore disappears. If something reactivates the virus, you’ll probably get cold sores again. They repeatedly occur in some people.
How long are you contagious if you have a cold sore?
You can pass the virus to others until the sores have scabbed over. So it’s important not to kiss others if you have a cold sore. You shouldn’t share food or drink while you’re contagious, just in case some of your saliva passed to another person.
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Symptoms of Cold Sores
If you’ve had a cold sore before, you may recognize the symptoms. Signs of a cold sore coming on include:
- Itchy skin.
- A tingling sensation.
- A feeling of numbness.
- Stinging and throbbing.
- Swollen lymph glands.
- Muscle aches.
What does a cold sore look like?
A cold sore is a fluid-filled blister. It can look red and irritated. Eventually, it breaks open, oozes fluid, and forms a crust.
Most cold sores are on the lips or around the mouth, but they can appear elsewhere on your face. If they are near your eyes, you should see a doctor right away. Left untreated, a cold sore near the eye could lead to a corneal infection, which could lead to blindness.
If you touch a cold sore and then touch another part of your body (for example, your genitals), you can spread the virus.
In healthy people, cold sores usually last five to 15 days. If your cold sore persists longer than that, you should see a dermatologist.
Preventing Cold Sores
If you’ve had cold sores once, you’re likely to get them again. There’s no cure for the virus, which stays in your body forever.
Cold sore triggers
Different stimuli affect different people. Your triggers might include:
- Having your period or other hormonal changes.
- An illness (cold, fever, flu).
- Injury to the mouth.
- Dental work.
Preventing the spread of cold sores
When you have an active cold sore, remember:
- Don’t kiss anyone.
- Avoid skin-to-skin contact with anyone with a compromised immune system.
- Don’t kiss or cuddle young children or babies, who are susceptible to catching the virus.
- Don’t share any personal items, such as towels, lipstick, or razors. Most cold sores spread through skin-to-skin contact, but the virus can survive for short periods of time on objects. (And it’s not a great idea to share germy personal items anyway.)
- Don’t touch your cold sores.
- Wash your hands frequently to avoid spreading the virus to another part of your body or to another person.
- Avoid anyone with eczema. The virus that causes cold sores can lead to a rare, life-threatening infection in people with eczema.
Best Cold Sore Treatment
Although there is no cure for cold sores, there are treatments available.
What is the fastest way to dry up a cold sore?
Most of the time, the best cold sore treatment is with over-the-counter products and at-home care. Try:
- Using a cold compress to ease discomfort.
- Applying over-the-counter creams and ointments. Look for products that contain docosanol or benzyl alcohol.
- Avoiding spicy or salty foods and acidic foods like tomatoes or citrus fruits. They can further irritate your cold sore.
- Taking acetaminophen (Tylenol) or ibuprofen (Advil) to help the pain.
- Wearing sunscreen. Lip balm with an SPF (sun-protection factor) of 30 or higher will help protect your lips while they heal.
When it’s time to call the doctor
Call your doctor if:
- Your sores don’t go away in two weeks.
- The cold sore is close to your eye.
- You also have HIV, AIDS, or another disease that weakens your immune system.
- You’re getting chemotherapy for cancer.
- The sores spread to another part of your body.
Your doctor may prescribe antiviral medication to treat your cold sores.
KidsHealth.org, Cold Sores (HSV-1), Link
American Academy of Dermatology, Cold Sores: Overview, Symptoms, Causes, Treatment, Self-Care, Link
American Academy of Dermatology, Cold Sores: Should I Keep a Child with Eczema Away? Link
NHS, Cold Sores, Link
U.S. National Library of Medicine, Herpes, Oral, Link
Canadian Public Health Services, Pathogen Safety Data Sheets: Infectious Substances – Herpes Simplex Virus, Link
MedicineNet.com, Cold Sores, Link
Medical News Today, Treatment Options for Cold Sores in the Early Stages, Link
Medical News Today, Everything You Need to Know About Cold Sores, Link
The UPMC Department of Dermatology diagnoses, treats, and manages numerous hair, skin, and nail conditions and diseases. We care for common and uncommon conditions, and our treatments include both surgical and nonsurgical options. We operate several specialty centers for various conditions. The UPMC Cosmetic Surgery and Skin Health Center is a comprehensive dermatologic laser facility, offering a full range of cosmetic services and procedures. With UPMC Hillman Cancer Center, we offer a Skin Cancer Program that provides complete care from screenings, diagnosis, treatment, and beyond. Find a dermatology provider near you.