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Canker Sore vs Cold Sore: How to Tell the Difference

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Jennifer Nelson
Written by Jennifer Nelson
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    How to Tell If You Have a Canker Sore vs. Cold Sore

    Whether inside or outside of your mouth, sores of any kind can make you miserable, and you want to make them go away as soon as possible. To do that, though, you have to know the difference between a canker sore vs. cold sore, since they have different symptoms and treatment.

    Continue reading to learn more about canker sores and cold sores, including their causes and how to get rid of them.

    How to Identify Cold Sores vs. Canker Sores

    How Do I Know If I Have Cold Sores?

    Cold sores usually appear around the lips, although they may also occur on the gums, tongue, or roof of the mouth. They are usually red, fluid-filled blisters that eventually ooze and scab over.

    Caused by herpes simplex virus type 1, cold sores are also known as oral herpes. Only people infected with the herpes virus get cold sores. Most people get infected with herpes as children through non-sexual contact, and about two-thirds of all adults carry the herpes virus.

    Once you have the herpes virus, you can get cold sores at any time. Some factors that may trigger cold sores include:

    • Stress

    • Excessive sun exposure

    • Cold, flu, or fever

    • Trauma to the face

    • Hormonal changes

    How Do I Know If I Have Canker Sores?

    Canker sores always appear inside the mouth. They are small, round ulcers that are usually white, grey, or yellow with a red outline. You’ll usually find canker sores:

    • Inside your cheek

    • Under your tongue

    • Inside your lip

    • At the back of your throat

    Many things can trigger canker sores, including:

    • Stress

    • Food allergies

    • Vitamin deficiencies

    • Hormone changes

    • Spicy or hot foods

    • Infections

    Symptoms of Canker Sores vs. Cold Sores

    What’s the best way to tell the difference between a canker sore vs. cold sore? Comparing the symptoms can be a helpful way to get answers. 

    Canker sore symptoms usually only include the sore itself. Canker sores are typically small, round sores that are grey, white, or yellow with a red border.

    Meanwhile, cold sore symptoms can include:

    • Tingling or burning before sores develop on or around the lips, mouth, nose, or other parts of the face

    • Headache

    • Body aches and pains

    • Fever

    • Sore throat or painful swallowing

    • Swollen lymph nodes

    • Nausea

    How to Treat Canker Sores and Cold Sores

    An optimal way to get rid of cold sores is with a prescription oral antiviral medication such as:

    • Acyclovir (Xerese, Zovirax)

    • Valacyclovir (Valtrex)

    • Famciclovir (Famvir)

    • Penciclovir (Denavir)

    Some other treatments that may ease your symptoms or help clear up the cold sores quicker include:

    • Ointments like Docosanol (Abreva)

    • Ice or a cold, damp washcloth

    • Aloe vera gel

    • Over-the-counter pain-relieving gels or creams containing benzocaine or lidocaine

    Canker sores usually clear up on their own within a week or two. However, there are some treatments you can consider for especially large or painful canker sores, such as:

    • Over-the-counter gels and creams

    • Prescription mouthwash with dexamethasone to ease swelling and pain

    • Oral medications, like steroids, for canker sores that don’t respond to other treatment

    Frequently Asked Questions

    What Causes Canker Sores?

    Canker sores can be caused by many things, including:

    • Stress

    • Nutrient deficiencies

    • Injury to the inside of the mouth

    • Hormone fluctuations

    • Use of mouthwash or toothpaste that contains sodium lauryl sulfate

    • Reaction to certain foods like nuts, chocolate, or spicy foods

    • Immune system conditions like lupus or inflammatory bowel disease

    What Causes Cold Sores?

    Technically, cold sores are caused by the herpes simplex virus. Once you have the virus, you can have cold sores at any time for the rest of your life. Things that can trigger cold sores include:

    • Stress

    • Exposure to sunlight

    • Fatigue

    • Cold, flu, or fever

    • Hormone changes

    • Irritation of the area where cold sores occur

    Are Cold Sores Contagious?

    If you have herpes, the virus that causes cold sores, you are technically always contagious. However, cold sores are the most contagious when the blister is oozing.

    How Can I Tell the Difference Between a Cold Sore and a Pimple?

    If you are prone to acne, though are not sure if you’re dealing with a pimple or a cold sore, you might be a little worried. Luckily, the differences between cold sores and pimples are often clear to determine.

    • Pimples are caused by bacteria and the overproduction of oil in your pores. While pimples may be red, they often have a white or black tip and may be filled with pus.

    • Cold sores are caused by the herpes virus. Unlike with pimples, you will usually feel a burning or tingling sensation before they appear. Rather than being filled with pus, cold sores are filled with a clear liquid.

    Can Canker Sores Be Caused by Stress?

    Yes, both canker sores and cold sores can be caused by stress.

    Get Canker Sore and Cold Sore Treatment Online

    If you have a canker sore or a cold sore that just won’t go away, you may have other treatment options. With online treatment at PlushCare, you can use your phone or computer to talk to a licensed doctor from the comfort of your own home.

    With PlushCare, you can book a video appointment with one of our trusted board-certified doctors to talk about your cold sore or canker sore. Our licensed physicians can provide a diagnosis, recommend treatment options, and electronically send your prescription to your local pharmacy.

    You can schedule an online appointment or download the PlushCare mobile app.


    Read More About Canker Sores vs. Cold Sores




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