Cold Sores 101

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Without a doubt, cold sores are one of the most frustrating, uncomfortable, seemingly unending, and surprisingly common skin infections people must endure. Not only are cold sores physically painful and unsightly, they also can be emotionally and socially debilitating. Adding to the embarrassment is the anxiety of knowing you must take steps to prevent spreading them to others because cold sores are extremely contagious.
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Cold Sore Facts

Despite their name, cold sores are not caused by a cold. However, because cold sores often erupt before or during a bad cold or other illness, when your immune system is suppressed, an association was formed and the name stuck. In truth, cold sores result from an infection with a type of herpes simplex virus known as HSV-1. This is not the same virus that causes genital herpes (known as HSV-2), but they are related.

Despite what some believe, cold sores are not canker sores. Canker sores are usually white, swollen, and inflamed lesions that occur inside your mouth. These sores are bacterial infections, not viral infections. They usually occur after you accidentally bite the inside of your mouth, and they are not contagious.

You may be surprised to learn that by some medical estimates, 80% of adults are infected with the virus that causes cold sores; however, among this group only 30% will experience cold sore outbreaks. Because the virus is so widespread, those who don't get cold sores are believed to have an extra ability to suppress the virus because their immune system produces more antibodies to fight the infection.

Once you have the virus that causes cold sores, you have it forever, because there is no cure. Even when a cold sore isn't visible, the virus hides out in your skin's nerve endings. The virus typically doesn't migrate, which is why cold sores tend to appear in the same area each time, year after year.

Without question, your first cold sore will be the worst. After being in close contact with someone who has a cold sore, you become infected. The first outbreak is often accompanied by fever, swollen lymph nodes, and generally feeling ill. After the first outbreak, aside from a suppressed immune system during a cold or other sickness, cold sores can also be triggered by stress, temperature extremes, sunlight (one more reason to apply sunscreen every day), and hormonal shifts such as those that occur during menstruation and menopause.

Here are some other cold sore facts to keep in mind:

  • The typical duration of a cold sore without treatment is 3 weeks. With treatment, most cold sores last less than a week.
  • Most who get cold sores suffer 2–3 outbreaks per year. It's a good idea to always keep a supply of oral or topical medication ready (including when you're traveling).
  • Cold sores can be triggered by a wide variety of factors, as mentioned above, and also by excess alcohol consumption, pregnancy, and steroidal medications (such as those for asthma).

What Cold Sores Look Like

Classic cold sores resemble a cluster of red, raised blisters. In fact, another name for cold sores is "fever blisters" because, just like other health issues that suppress the immune system, having a high fever can cause an outbreak in those with the HSV-1 virus. Cold sores usually occur around the mouth, often on the border between the lip line and the skin around the lips. The blisters range in size from the diameter of a pencil eraser to a small coin.

Although cold sores are most often seen around the mouth, they also can appear on the cheeks, chin, or nose. Cold sores rarely appear on other parts of the body. Regardless of where they show, cold sores are usually filled with a clear fluid, which eventually oozes out and then dries, forming a crust-like scab over the sore. The scabbed area may be larger than the cold sore itself.

Before you see a cold sore, you'll often feel a tingling, itching, or burning sensation in the area where one is about to appear. This may happen a few hours to a few days before the cold sore rears its ugly head. This is the time to begin topical medication; doing so can prevent a cold sore from erupting and shorten the healing time.

Treating Cold Sores

Although cold sores are a nuisance and the virus that causes them cannot be cured, there are several treatment options to manage the infection, reduce discomfort, and speed healing time. Most cold sores respond best to oral or topical prescription treatments (some cases require both at the same time), but there are over-the-counter alternatives, too.

Oral prescription drugs used to treat cold sores are Zovirax (acyclovir), Famvir(famciclovir), and Valtrex (valacyclovir). All of these work by interrupting virus replication in the first few days of an outbreak. By reducing viral replication, the skin's immune system stands a better chance of handling the infection, causing the virus to go back to its latent (inactive) state. Follow your physician's dosage instructions for these medications, and note that the active ingredient in Zovirax (acylclovir) is available for topical use, too.

Among the topical prescription medications for treating cold sores, Denavir (penciclovir) Cream is widely considered to be the best. This medication accelerates healing, helps minimize viral shedding (making you less infectious), and reduces pain. For best results, apply at the first sign of a cold sore and then apply throughout the day (at least every 2 hours while you're awake) for 4 days.

Abreva (docosanol) is the chief topical over-the-counter option to treat cold sores. It should be used at the first sign of a cold sore and applied at least 5 times daily until the cold sore is gone. Although Abreva generally is not as effective as prescription options, it is worth trying and is significantly less expensive.

You may have heard that topical application of lemon balm, rhubarb with sage, and tea tree oil helps treat cold sores, but there is little convincing research that these work all that well, and they don't work better (or faster) than the standard prescription options. Most of these can cause irritation that may make cold sores look and feel worse, and they might even delay healing.

Along with prescription or over-the-counter medications, here are additional tips for treating cold sores:

  • With any cold sore treatment, it's a good idea to apply an antibiotic ointment such as Polysporin to the area. This helps prevent the open sore from becoming infected with the bacteria normally found on skin. Secondary bacterial infection is an issue when the cold sore's blister breaks, leaving that area of skin vulnerable. Apply the ointment after applying the cold sore medication.
  • Those with chronic cold sores (more than one outbreak every 2–3 months) may want to consider a regimen of low-dose antiviral drugs to minimize or potentially eliminate outbreaks. Discuss this option with your physician.
  • The amino acid L-lysine is a popular natural remedy for cold sores, but there is little research proving it's widely effective. Still, it isn't harmful, so you can try this oral supplement to see if it helps. L-lysine is also available for topical use.
  • Use a lipstick or lip balm with sunscreen religiously, even when cold sores are not present, but for hygiene reasons, once your skin has healed, replace any lip balm that you used over an active cold sore. Visit Beautypedia for other recommended lip balms with sunscreen.

Cold Sore Precautions You Must Know

There is some confusion about when and for how long cold sores are contagious and what precautions you should take during an outbreak. Follow the guidelines below and you'll be doing all the right things to avoid spreading cold sores or making an existing infection worse:

  • You cannot pass cold sores to others when they are not visible because the virus that causes cold sores doesn't shed viral particles unless a blister is present. Without a visible cold sore outbreak, you are not contagious.
  • Avoid skin-to-skin contact (no kissing) when a cold sore is visible or when it's healing; the virus can be spread in this manner and during these times.
  • A cold sore must be completely healed for it not to be contagious.
  • Do not share drinking glasses, straws, utensils, toothbrushes, or lip-care products until the cold sore has healed completely.
  • Always wash your hands after you touch a cold sore. It is possible to spread the virus to other parts of your body if it remains on your fingertips. For example, rubbing your eyes after touching a cold sore can transfer viral particles to this area, resulting in serious problems.
  • Don't itch or pick at cold sore scabs! We know it's hard to leave a cold sore alone, but if you don't it will prolong healing, increase the risk of scarring, and potentially spread viral particles to other areas, leading to more cold sores. If the scab becomes uncomfortably dry or itchy, apply a thin layer of an antibiotic ointment and/or apply warm compresses.

Using Makeup to Hide a Cold Sore

When a cold sore hits, you'll most likely want to conceal it as you treat it. Due to the delicate texture and eventual scabbing-over of cold sores, this is easier said than done—but it can be done! The trick is to use a lightweight concealer that doesn't drag over the skin and that also provides good coverage from just a small amount of product that you can apply carefully and layer precisely.

We outline the steps for concealing a cold sore below, but remember: If using makeup to cover a cold sore makes the sore or the scab more obvious, it's best to skip the cover-up, be patient, and just let it heal:

  1. Make sure the skin around the cold sore is clean and dry; you may need to apply a thin layer of moisturizer or dab the area with a soothing toner, but take extreme care to not disturb or rupture the cold sore.
  2. With a stippling brush (one we like: Sephora Collection I.T. Stippling Brush, $32) apply a thin layer of liquid or cream concealer to the cold sore and the surrounding skin. Use a gentle stippling motion (soft, circular tapping movements) and repeat until desired coverage is achieved. Visit Beautypedia for our list of best concealers.
  3. Use clean fingertips or a makeup sponge to blend and feather the edges of the concealer into the surrounding skin. As you do this, avoid the sore itself because any pressure can rupture the lesion.
  4. Set with a light dusting of loose or pressed powder. A pressed powder with sunscreen will provide an additional measure of sun protection as the cold sore heals.
  5. Check your results in natural light to make sure the area doesn't look caked or too dry, both of which will call more attention to what you're trying to hide.

When painful and unsightly cold sores show up, we understand you have every reason to want them gone as soon as possible. Following these steps and experimenting to find what works best for you can treat them as effectively as possible, so you can get through an outbreak with minimal discomfort and avoid spreading the infection to others.

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About the Experts

Paula Begoun is the best-selling author of 20 books on skin care and makeup. She is known worldwide as the Cosmetics Cop and creator of Paula's Choice. Paula's expertise has led to hundreds of appearances on national and international television including:

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The Paula's Choice Research Team is dedicated to helping you find the absolute best products for your skin, using research-based criteria to review beauty products from an honest, balanced perspective. Each member of the team was personally trained by Paula herself.

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