Clinical TopicsDermatologyInfection PreventionInfectious DiseasesPatient SafetyYour Health

Common sense about cold sores


You have been looking forward to your nursing class reunion for months. The day finally arrives; but to your horror, a large cold sore has appeared! It’s ugly and painful. Is there anything you can do?

What is a cold sore?

A cold sore is one or a series of fluid-filled blisters on or around the lips, nose, cheeks, or hard palette of the mouth. Often referred to as a fever blister, cold sores are caused by the herpes simplex virus (HSV) and are contagious. Spreading lesions are a characteristic of herpes, which is an ancient Greek word meaning “to creep or crawl.” The two types that cause infections are HSV-1 and HSV-2. HSV-1 is the most frequent cause of blisters in the facial area; HSV-2 more commonly produces genital sores. However, both may cause lesions in either area.

Canker sores (minor aphthous ulcers) are often confused with cold sores. Cankers are found inside the mouth and are not infectious. Xu, Sternberg, Kottiri, et al (2006), estimated 57% of U.S. adults are infected with HSV-1. In a 2008 study, Hobbs, Jones, Otterud, Leppert, & Kriesel found the majority of Americans are infected with HSV-1, HSV-2, or both; however, HSV-1 is the most common recurring viral infection in humans.

While the exact trigger of an outbreak is not always known, the initial infection results from contact with another person who is actively shedding the herpes virus. You may only experience a fever with the primary infection; however, once acquired, the HSV-1 virus lies dormant in the sensory nerve ganglia until it is reactivated.

Cold sore stages

Cold sores progress through five stages and generally last 7-12 days before the scab falls off and healing is complete:

  • Stage 1 is referred to as the prodrome, or tingling, stage and usually lasts several hours to 2 days. In most cases, the area of tingling will swell and redden, and it may be sensitive to touch and palpable near the previous cold sore. Interestingly, a third of the infected population will experience cold sores in the same area with each recurrence.
  • Stage 2 occurs when the area becomes a fluid-filled blister or a cluster of smaller blisters. This usually happens within 48 hours.
  • During stage 3, blisters break open, leaving a noticeably moist area. Weeping occurs, and the area is generally painful for approximately 3 days. Cold sores are contagious at all stages; however, stage 3 is considered the most infectious due to serous fluid draining from lesions filled with the HSV virus.
  • Scabbing, or stage 4, lasts 2 or 3 days and is associated with cracking, bleeding, and occasional itching and burning at the site.
  • This scabbing process takes place until the sore finally disappears at stage 5.

Diagnosing a cold sore

Many events can cause activation of the virus, such as tissue damage, physical or emotional stress, ultraviolet light, and fever. Reactivation increases with aging and immune suppression, and it may be triggered by fever, systemic infection, cold symptoms, menstruation, increased physical and emotional stress, increased sun exposure, and tooth extraction.

To diagnosis a HSV-1 cold sore, it is important to know when the initial symptoms appeared, if there was pain at the site, and when blistering developed. Additionally, details about predisposing factors are helpful with diagnosis. Healthcare providers should be aware if a patient has a suppressed immune system, lesions that fail to heal within the accepted time frame, developed severe symptoms, or frequent colds.

Treating a cold sore

While there is no cure for cold sores, the clinical symptoms may be treated with over the counter agents, antiviral suppressive therapies, and homeopathic remedies. Some of the more common OTC treatments are topical anesthetics containing benzocaine, lidocaine, tetracaine, and dibucaine. Docosanol (Abreva) is an OTC antiviral drug that has been available since 2000. According to Woo and Challacombe, docosanol has been shown to be an effective treatment for decreasing the healing time of cold sore lesions.

Prescription antiviral medications limit the virus’s ability to multiply. Penciclovir (Denavir) is a topical cream that is used to treat mild, recurrent HSV-1 outbreaks, reducing pain and healing time. Other medications include acyclovir (Zovirax) ointment and two oral agents: famciclovir (Famvir) and valacyclovir (Valtrex). Women should avoid acyclovir without physician approval if they are breastfeeding or plan to become pregnant.

Natural remedies are available, including Enzymatic Therapy Cold Sore Relief with allantoin, Montana Big Sky Extra Thick Propolis Tincture, and Quantum Health Super Lysine+ Cream. Reduction of swelling and pain can most often be accomplished by using anti-inflammatory medications, such as acetaminophen and ibuprofen. Avoid squeezing or picking the blisters, and keep the area moist to reduce painful cracking and bleeding.

Prevention is key

Maintaining your health is important in reducing the number of cold sore outbreaks. If you believe you are developing a cold sore or already have one, avoid kissing and oral sexual contact. Do not share food, drinks, cups, or eating utensils. Avoid sharing razors, towels, lip-gloss, or lipstick. Keep your hands away from the affected area, and do not touch your eyes. If you do touch the blistered or weeping site, wash your hands immediately with soap and water. Identify high stressors, and use strategies to avoid or reduce stressful situations. Keep your lips moist with lip balm or petroleum-based products. Reduce exposure to hot sun or extreme cold, wear sunscreen with an SPF of 15 or higher, eat a well-balanced diet, exercise, and obtain sufficient rest.

Juanita Ebert Brand is an assistant professor in the school of nursing at Ball State University in Muncie, Indiana and nurse researcher at the Marion County Health Department in Indianapolis. Cynthia Thomas is an assistant professor in the school of nursing at Ball State University.


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1 Comment.

  • Tracy Crane
    March 4, 2023 1:21 pm

    I took part in a research project which involved a two day trip to Florida to the Herpes Simplex Virus HSV-1 & HSV-2 Disease Centre, We had the opportunity to meet with World Rehabilitate Clinic Herbs, A highly recommended herbal formula with scientific medicine. I began healing herbs from ( worldrehabilitateclinic. com and within then first weeks I was already seeing improvement, I was cured within 2 months I was cured completely. I would encourage anyone to seek a second opinion especially if they’ve been told there’s no hope. It’s also crucial to learn as much as you can about your diagnosis. Seek options. Find out about what’s out there that could help.

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