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    Is it a Cold Sore or a Fever Blister?

    Is it a Cold Sore or a Fever Blister?

    cold sore or fever blister

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    Imagine this: You and your mother are having a heated discussion about whether the sudden appearance of a sore on your lip is a fever blister or a cold sore. You know you can win this battle, and you respond with an I’ll-show-you retort: "Let's ask Mr. Google," you say. Both of you whip out your smart phones, and ...a family crisis is averted. It turns out you’re both right, according to John Hopkins Medicine. Case in point, this annoying sore is known by both names, and is caused by the virus "herpes simplex," or oral herpes (HSV-1).

    Causes and Symptoms of Fever Blisters and Cold Sores

    Now, before you get fixated on the word "herpes," you need to know that oral herpes (HSV-1) is not the same as genital herpes (HSV-2). While both are contagious, your cold sores and fever blisters will usually show themselves in or around the mouth.

    When a person first contracts the virus (how you get the virus will be discussed later), the initial breakout will occur in a few days, and can be accompanied by a fever, sore throat, aches and pains, and a headache. Unfortunately, when you’re feeling better after your first outbreak, the fun isn’t over. The virus doesn't leave your body: it simply remains dormant in your nerve cells. This means you can have reoccurrences throughout your life, because there's no cure for HSV-1.

    Fortunately, the reoccurrences won't likely be as bad as the first one. The next cold sore will likely start off with a prickly or tingling and itchy feeling, small bumps in and around your mouth, and quickly turn into "fluid-filled blisters that rupture after a day or two."

    Here comes the distasteful part (pun intended): According to the Department of Dermatology at the Mayo Clinic, the fluid from the burst blister contains the HSV-1 virus, and the cold sore virus can be spread to others by skin-to-skin contact, such as kissing, sharing lip balm and hand towels, or stealing that last bite of food off of your friend's fork. While you shouldn't revert to becoming a complete viro-phobe — a close psychological cousin to the germaphobe — you should know you can also get the HSV-1 virus by touching something an outbreak victim has touched if you touch your mouth afterward. As your mother always says, "Wash your hands…you don’t know who’s touched that!"

    Following the burst of the blister, the fluid will ooze out, sometimes turning into a crusty covering and forming a scab over the open wound, which is tender to the touch, and can crack open. An outbreak, from the first initial tingle to the scab falling off, typically lasts from seven to 10 days.

    Cold Sore/Fever Blister Remedies

    Cold sore remedies can range from natural home-based cures to over-the-counter treatments and doctor-prescribed medicines.

    Cold Sore Home Remedies

    If you prefer to try a natural cold sore remedy, many common items are purported to prevent and/or lessen the irritation of outbreaks. Some of these remedies are listed below, although definitive research is still limited as to their effectiveness.

    • Lysine: An oral supplement or ointment, found in the pharmacy or health store supplement section, may prevent outbreaks, or lessen its duration. Use as directed on the bottle.
    • Lemon lip balm or lemon tea:Use a lip balm with at least 1 percent lemon, or you can use a cottonball soaked in strong lemon tea (used as a compress, held in place for a few minutes, and repeated several times a day).
    • Aloe Vera: The preferred usage is applying fresh gel directly from the easily-maintained plant in compress form, but a store-bought pure aloe vera gel can also be used. Aloe vera is often used for treatment of skin problems, and can help prevent a bacterial infection from developing in the open sore.
    • Real vanilla extract: The alcohol in the extract keeps the area clean and may make it harder for the virus to flourish. Apply compress-style as soon as you feel the first tingling sensation, and use until no longer needed. NOTE: There is some discussion as to whether an open sore heals faster when kept dry (which is enhanced by using an alcohol-based product) or moist, (which results from using an ointment such as petroleum jelly). Trial and error will let you know what works for you. However, once a scab is formed, an ointment can reduce the chances of the scab cracking, causing more pain, and increasing the chance of a secondary infection.
    • Licorice powder: Unfortunately, chowing down on your favorite brand of black licorice won't do the trick on this one. Use licorice powder mixed with water or petroleum jelly to form a paste, and apply it to the affected area several times a day — or even better, right before bedtime so it can stay there all night. Licorice is often used for fever blister treatments because it’s thought to have anti-inflammatory and anti-viral properties.
    • Milk: It's not just for babies anymore! Milk contains L-Lysine and proteins known as immunoglobulins (the little soldier cells your body produces to fight off infections). To prevent outbreaks, drink whole milk. To help cold sores that have already erupted, use a whole-milk compress.
    • Peppermint oil: This natural remedy kills the virus cells when applied directly to an open wound. Unfortunately, the oil can't soak through your skin, so this isn't a preventive measure. Add peppermint oil to a little water and use in compress form.
    • Hydrogen peroxide: Yes, that cure-all your mom poured on every ailment actually IS a disinfectant, and can help prevent an open sore from creating another sore. Use in compress form.

    If you're not successful in staving off the sore, applications of ointments and petroleum jelly will help keep the scabs from cracking open, helping to reduce the pain and shorten the time of recovery. It's "generally true that wounds heal more quickly when kept moist," according to Clark Otley, MD, the chair of the Department of Dermatology at the Mayo Clinic.

    RECOMMENDATION: Talk to your doctor about any supplements or medicines to see if your situation may warrant avoiding certain products.

    Over-the-Counter Medicines

    Several over-the-counter medicines are commonly used to treat cold sores. Although they're not usually as effective as prescription medicine, they can often bring the relief you seek, especially if you don't have a prescription but feel you may be at the onset of an outbreak.

    • Abreva and Zilactin can help the sore disappear more quickly, and some people find they can stop a severe outbreak if applied soon enough.
    • Orajel and Anbesol are used to reduce the pain of the sore.

    NOTE: According to WebMD, "Children age 2 and older can be treated with Zilactin-L Liquid, Orajel Baby, and Anbesol. Abreva is for people age 12 and older, so talk to your doctor before using it for a younger child."

    RECOMMENDATION: Talk to your doctor about any supplements or medicines to see if your situation may warrant avoiding certain products.

    Prescription Treatments

    Many physicians will take your word for it if you tell them you're prone to outbreaks. Describe to them, in graphic detail, your experiences with cold sores, and they'll be happy to offer you the medicine you need. Your physician will most often prescribe one of several effective treatments. These antiviral medicines can include (but are not limited to) acyclovir (Zovirax), famciclovir (Famvir), and valacyclovir (Valtrex). These medications are most effective when started within the first 48 hours of the outbreak. Prescription medicines have been very successful in reducing the severity of the outbreak for thousands of fellow-suffers, and many years of clinical testing have verified their effectiveness.

    RECOMMENDATION: Be sure your doctor knows about all the medicines you're currently taking to see if your situation may warrant avoiding certain products.


    Cold sores can appear at the worst times. In fact, you may start to recognize what triggers an outbreak for you. Some of the common triggers are fever, stress, fatigue, sun exposure, and even menstruation. Obviously, some of these triggers you can avoid and some you can't. But these triggers can be warnings to get your favorite remedy ready to fight the battle.

    There are some practical things you can do to lessen the number of outbreaks or reduce their severity. Here are just a few common-sense ideas.

    Use Sunscreen

    Sunscreen, in addition to keeping you from looking like an old raisin and helping you avoid skin cancer, can also help prevent an outbreak. It's a good habit to apply sunscreen to your face, and apply lip balm with no less than SPF15.

    Don't Touch

    You may want to scratch at the newly-formed bumps. Don't! This will only irritate the area and help the blisters to break. Then, you can spread the HSV-1 virus to other locations.

    Use Ice

    Applying a soft ice pack to the sore can reduce the tenderness of the area. Be cautious to avoid leaving the ice pack on the area for too long, or you'll be adding frostbite to the list of your woes. Apply the wrapped ice pack to the area for a few minutes, then remove it, wait a few minutes, and re-apply. Repeat as needed.

    Trade-in Your Toothbrush

    Get rid of your toothbrush after a fever blister has formed, and get rid of it again once the sore is gone. Otherwise, your toothbrush will have the fresh HSV-1 ooze on it, just waiting to give you an encore breakout.

    A Serious and Final Caution

    The virus that causes HSV-1 (oral herpes) can become HSV-2 (genital herpes) if someone infected with HSV-1 has oral contact with the genitals of another person. Genital herpes is very contagious, incurable, and outbreaks can be very painful. (For more information on genital herpes, access the Center for Disease Control and Prevention (CDC) website at


    What is a fever blister? What is a cold sore? They’re the same thing: an annoying, painful, and embarrassing sore that appears in or around your mouth, caused by the HSV-1 virus.

    Remember, once you've grown a fluid-filled blister, you can potentially and easily share this virus with others if you're not careful. Perhaps this is why nearly 90 percent of adults in the U.S. have the HSV-1 virus in either active or dormant forms. But if you end up getting some form of HSV-1, don't despair. It's about as common as the common cold and treatment options are readily available.