Are Cold Sores Contagious? Here’s What to Know
Medical Review By: Camila Yepes, PA-C
Cold sores, aka fever blisters, are caused by the herpes simplex virus (HSV) — not by colds or fevers. But like colds, they are very contagious. You can spread HSV at any point from the first warning tingle up until the cold sore scab has completely disappeared. It’s even theoretically possible to spread the virus when you don’t have a cold sore.
Read on to learn more about cold sores and how to stop the spread.
What causes cold sores?
Oral herpes infections are spread from person to person, usually through direct contact — for example, through kissing or oral sex. They can also be spread by sharing personal items such as drinking glasses or lip balm.
Of course, you can develop a cold sore without coming into contact with someone who has one. That’s because most adults have already been infected with HSV, typically during childhood, and the virus remains in the body, hiding in nerve cells, for life.
Certain triggers can “wake up” the virus, resulting in a cold sore. These include sun exposure, cold wind, cracked lips, hormonal changes during menstruation or pregnancy, emotional stress, surgery, and anything that taxes your immune system, such as the common cold or another illness.
Cold sore stages
Stage 1: You’ll feel tingling, itching, or burning somewhere around your mouth or at the base of your nose. You’re already contagious at this stage (called the prodome stage). This is the time to apply an over-the-counter product such as Abreva or take an oral antiviral medication such as valacyclovir if your doctor has prescribed one. Valacyclovir is highly effective at shortening outbreaks when taken within the first 24 hours of symptoms.
Stage 2: After a day or two of tingling, blisters filled with clear liquid develop and the skin under and around them reddens. Cold sores spread easily at this stage. Do not break the blisters.
Stage 3: A few days later, usually on day four, the blisters break on their own, creating an open sore. This stage, which doctors call the ulcer or weeping stage, is when a cold sore is the most contagious.
Stage 4: The sore starts to dry out and scab over. It may crack or bleed. The sore is still contagious.
Stage 5: The sore begins to scab over. When the scab falls off, the area may look pink or red for a few days. The sore is no longer contagious once the skin heals.
Stopping the spread
Cold sores can spread through saliva and through skin-to-skin contact. To avoid infecting other people, follow these tips during every stage of a cold sore.
Avoid touching the area. If you must scratch when it itches, wash your hands thoroughly afterward. Apply any topical treatments with a cotton swab, not your finger. Don’t pick at the scab (this will only prolong the healing process).
Don’t share any personal items. This includes food, drinks, eating utensils, straws, toothbrushes, razors, lip balm, petroleum jelly and any cold sore cream or ointment you use.
Don’t kiss anyone or nuzzle your baby. Kissing your baby while you have a cold sore is dangerous because the virus is far more severe in infants, who don’t have a fully developed immune system. You should also avoid close contact with anyone who has a weakened immune system, and anyone who has eczema. People with eczema are at risk of a potentially serious skin infection called eczema herpeticum.
Refrain from oral sex. Genital herpes is typically caused by a different strain of HSV (HSV-2), but it is possible for your partner to develop “oral herpes” (HSV-1) on their genitals from exposure to a cold sore on your mouth.
The best way to avoid spreading cold sores is to avoid getting them in the first place. While you have limited control over some common triggers, you can lower your risk of outbreaks caused by sun exposure by wearing lip balm with an SPF of at least 30.
If you get cold sores several times a year, ask your Water's Edge dermatologist about a prescription for an antiviral medicine to take at the first sign of an outbreak. People who get cold sores many times a year may be prescribed a low-dose antiviral medication to take daily in order to help prevent outbreaks. Taking supplements of the amino acid lysine coupled with avoiding foods high in the amino acid arginine (notably, nuts and seeds) may help, too.
Get Cold Sore Treatment, Contact Our Dermatologists Today!
Article Written By: Jessica Brown, a health and science writer/editor based in Brooklyn, New York. She has written for Prevention magazine, jnj.com, BCRF.org and many other outlets.
Medical Review By: Camila Yepes, PA-C
Common Viruses of the Skin & What You Should Know
Common viruses of the skin include Molluscum Contagiosum, warts, and Herpes Simplex Virus Type 1 and 2. These viruses are common because they are contagious with skin to skin contact. Although most are only an annoyance, some do have the potential to cause harm to the person affected. Our goal at Water’s Edge Dermatology is to educate and alleviate any possible concerns of our patients.
Molluscum Contagiosum is a common skin condition, especially in children, that comes from the Poxvirus. The virus presents as small umbilicated blisters and is usually diagnosed by a trained eye but can be confirmed with a biopsy. Contagiosum is an adjective that well describes the condition because it is so contagious. Children have more skin-to-skin contact and a lower immunity than adults, explaining why it is more commonly seen at a younger age. There are treatments such as liquid nitrogen or Cantharone (a topical agent) that are often used if the condition is bothersome or spreading. Treatment is not necessary because Molluscum Contagiosum is not harmful and with time should go away on its own. This condition can be sexually transmitted, but more commonly is spread by touching or scratching the area. Helpful tips for prevention include: avoiding direct skin-to-skin contact, avoid sharing towels with someone who is infected, frequent hand washing and protecting the skin's barrier by keeping it well moisturized.
Warts are caused by a virus called the Human Papilloma Virus (HPV), which is easily transmitted. Warts are also more common is children because their immunity is lower than adults. Most often, warts are diagnosed by a trained eye but can also be confirmed by a biopsy. There are different types of warts including; common warts, flat warts, plantar (under the surface of the foot) warts, and genital warts. Treatment may be the same as for Molluscum Contagiosum and is also a condition that may resolve on its own. Warts are typically raised but can be flat as in the flat warts or on the plantar surface of the foot. If warts are found in the genital region, they are usually considered to be sexually transmitted. However, common warts can also be transferred to the genitalia. Warts can be eradicated with treatment but they can return. Women who have a partner diagnosed with genital warts are at a higher risk for cervical cancer and should have regular pap smears. Helpful tips for prevention include: frequent hand washing; avoiding skin-to-skin contact with affected areas; wearing shoes in locker rooms, water parks, public pools and public showers to protect the feet; and protecting the skins barrier by keeping it well moisturized.
Herpes Simplex Virus (HSV) has two types (I and II), that when active, present with blisters or sores that can be painful. Type I is the cold sore virus and is generally found on the face, and type II is the sexually transmitted virus that is typically found in the genital area. However, type I has been found in the genitalia and type II has been found in other parts of the body. Once exposed to the virus, it may lay dormant for a long period of time, or may be such a mild case making it difficult to identify the source of infection. Stress and sun exposure can activate the dormant virus. HSV is contagious during flares but can also be contagious when no lesions are present. HSV is most commonly diagnosed by a trained eye, but a viral culture or blood work can be taken to confirm the diagnosis. HSV is treatable but there is no cure. Symptoms that may indicate the virus is active include tingling, itching, tenderness or burning sensation in the affected area. The treatment is antiviral medications like acyclovir or valacyclovir. If the medication is taken at onset, the symptoms may be minimized and the duration may be shortened. The symptoms will go away on their own with no treatment but may take longer than with the medication. Tips for prevention include: avoiding skin to skin contact to the affected area of a person with known HSV and avoiding sharing drinks, towels, lip balms or other products that may come in contact with the affected area.
These are some of the most common viruses of the skin but certainly not all of them. The key is early diagnosis and prompt treatment for any condition. Proper hand washing may not prevent these conditions, but is the number one way to avoid spreading infections. If you have any questions, please fill free to contact any of our offices. We are happy to help you in any way we can.