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How common are cold sores, fever blisters?
What is a Cold Sore, Fever Blister?
Are cold sores just a trivial disease that will go away anyway?
What causes Cold Sores, Fever Blisters?
What causes a recurrent cold sore outbreak?
How is the Cold Sore Virus transmitted?
What are the signs and symptoms of a cold sore?
What happens to the Cold Sore Virus once it enters through the skin?
What can be done to prevent Cold Sores from spreading?
Prescription (Rx) Treatments
Treatments Not Approved By FDA
What do I need to remember about Cold Sores / Fever Blisters?
How common are cold sores, fever blisters?
By adulthood, over 90% of people in the United States are exposed to one or more of the viruses in the family that includes the cold sore virus. Scientists do not know why, but not everyone who is exposed to the virus develops recurring cold sores. About 40% of people exposed to the cold sore virus experience one or more lesions per year.
What is a Cold Sore, Fever Blister?
Many people are not aware that Fever Blisters and Cold Sores both refer to the same thing, an infection on the lips caused by the human herpes simplex virus, usually type 1 (HSV-1). A cold sore typically begins as an itch, tingle, or tenderness to the touch (prodrome), and progresses on to become a skin eruption. As the disease progresses, small fluid filled vesicles may form and join together. These eventually break due to disease progression and form ulcers. The ulcers may weep fluid when they are open. They are very contagious at this time. The ulcers then scab over and heal spontaneously without complications in 7-14 days.
Cold sores / fever blisters usually occur on or very near the lips. Some people may get more than one cold sore at a time. Some people may get them under the nose and in surrounding areas. Less frequently other parts of the body (arm, finger, leg, eye) can become infected, as well. Cold sores can be very embarrassing for some people. Fear of embarrassment can lead some to compromise their work or school responsibilities.
Not quite half the people who are exposed to HSV-1 get cold sores more than once in their lifetime. Some people may get a cold sore 4 or more times per year. Some will get only one or two per year. Still others may have them only once in their lifetime.
Many people who are infected don't even know it. They are a significant reason there is a burgeoning epidemic of HSV infection around the world, as these people unknowingly spread the disease to uninfected people.
Are cold sores just a trivial disease that will go away anyway?
In most people, cold sores can be very painful and can be an extreme social embarrassment. But, even though most people heal in about 10 days after having a painful lesion, cold sores are not just a trivial disease. When the cold sore virus is accidentally transmitted to a baby or somebody with a weakened immune system, the results can be disastrous. Serious infections can lead to death.
Infection of the eyes can lead to blindness.
What causes Cold Sores, Fever Blisters?
In almost all cases, cold sores / fever blisters are caused by the Herpes Simplex Type 1 virus (HSV-1). Herpes Simplex Type 2 (HSV-2) is usually associated with genital herpes. Due to changing social practices, such as an increase in oral sex, there is now overlap with HSV-1 being found in a substantial number of first episodes of genital herpes cases diagnosed by a doctor. (HSV-2 however is rarely associated with cold sores, as HSV-2 infection on the face does not tend to recur.) Medical scientists who study herpes have written that a combination of education and effective products to control cold sores may help prevent the transmission of the cold sore virus to the genital area.
Although Oral (cold sores) and Genital Herpes are typically area-specific, herpes infections can occur anywhere on the body. Inadvertent touching of an HSV sore during an episode of infection, followed by touching another part of the body can spread the infection to less traditional locations. Once infection has been established in an area, it can recur in the same place. Accidental infection of another part of the body is less common in people with a history of cold sores, but it can happen. People who get cold sores should take care not to touch other parts of the body after touching a cold sore.
Another herpes virus of note is the Varicella-Zoster virus, which causes chicken pox in children and shingles (herpes zoster) in older people.
What causes a recurrent cold sore outbreak?
Following the primary infection, the herpes virus becomes latent (it goes to sleep) deep inside nerve cells. Scientists are not yet sure why some people have many cold sore recurrences per year and yet others seem to be protected and may not get lesions as often or at all. Recurrent infections can be triggered by many different stimuli. The most common cold sore "alarm clock"s are fever (ergo "fever blister"), and exposure to the sunlight (UV-B). Other stimuli include localized trauma to the mouth (such as dental work and cosmetic procedures to the face), other illness, and emotional stress. For some individuals, recurrences are unpredictable and have no recognizable cause. Others are very aware of what kinds of events will likely lead to recurrences and can anticipate the need to begin treatment as early as possible in an acute episode.
How is the Cold Sore Virus transmitted?
The cold sore virus is typically transferred through direct or indirect physical contact. Examples of direct contact include viral transmission during kissing or other intimate behaviors. Indirect contact can occur when live virus is transferred between children putting commonly shared objects into their mouths, use of someone else's face cloth, drinking from a common cup or glass and sharing of cosmetics, such as lipstick. Often, transmission is between family members due to normal contact. A kiss from a friend or relative when he or she has a lesion can introduce the virus to a person who may not have been previously exposed.
The virus can remain active as long as it remains wet. One typically does not get infection from casual contact or contact with hard surfaces. It is now well known that transmission is possible, without the presence of an active lesion. Some people shed the virus in saliva without any other symptoms about 5 - 15% of the time.
There are two distinct periods in life when people are likely to be exposed to HSV-1. The first is early childhood (age 3 to 7) and a second period occurs in adolescence (age 12 to 21). Transmission is via close or intimate physical contact.
What are the signs and symptoms of a cold sore?
When a clinical infection occurs for the first time in an individual, it is called a primary infection. Primary HSV-1 infection is often sub-clinical (no recognizable symptoms) and thus goes unnoticed, or it may be severe and may cause gingivostomatitis that ranges from mild to severe, the latter of which may be accompanied by enlarged and tender lymph nodes in the neck and under the jaw, swelling of the throat, fever and malaise. There may be "satellite" sores on other parts of the body. People who get cold sores after their primary exposure are said to have recurrent cold sores Primary infection can have lesions and symptoms that persist for 3 to 6 weeks.
Prior to a clinical outbreak of a recurrent cold sore episode, many people experience a prodromal phase, which includes an itchy, tingling sensation on the soon-to-be-affected skin. Often there is a warm or burning sensation with tenderness to touch soon thereafter. As the disease progresses, the area becomes red and raised. Tiny fluid filled bumps called vesicles form and join together. As the disease progresses, these blisters rupture leaving tender, fragile ulcers that release clear fluid-filled liquid containing the herpes viruses. Sometimes they bleed. The release of clear fluid is called weeping. When weeping is taking place, the infection is very contagious. As the ulcer heals, a scab forms and eventually falls off when healing is complete.
Some people experience secondary events when a new viral load travels out of the infected nerves and infects adjacent skin areas. When people begin to feel better and then appear to get worse, or get a new cold sore on top of or near the older one, this is usually due to secondary events. Experiencing a secondary event, especially after a lesion has been present for a couple of days, can extend the time the cold sore is active and painful.
What happens to the Cold Sore Virus once it enters through the skin?
After getting a cold sore, a scab forms and the skin heals, usually with no residual scar. During primary infection, and in subsequent recurrent infections, the virus invades the body and infects skin cells. After first infecting a skin cell, the infection continues from cell to adjacent cell until the virus finds its way to the sensory nerve cells that supply that area of skin and surrounding area. The virus infects the nerve and goes to sleep. Later, triggers q wake it up and the re-infection process begins. In this way the virus becomes a permanent resident of the body
Here is how the process works in detail. The HSV-1 virus consists of viral DNA that is encased in lipids (fat). During the primary infection, the virus infected many skin cells of the lip and eventually infected enough skin cells to find the end of sensory nerves known as a terminal neuron. This is the part of the nerve that feels. The herpes virus sheds its coat and enters the nerve by going through the terminal neuron. It then migrates up the shaft of the nerve and finally goes latent (goes to sleep) in the nerve cell body. Clusters of sensory nerves all terminate in what are known as ganglion. During the infection process, countless nerves are infected.
When the virus wakes up due to one or more stimulating triggers, it exactly reverses the path it took and reassembles a lipid coat as it exits the terminal neuron. The virus then infects a nearby cell in the lip, multiplies itself using cellular material stolen from the host cell, kills the host cell, and then these new viruses go on to infect more adjacent cells until the infection results in a lesion.
Sometimes the virus can wake up and not cause a lesion. In this case, the virus can still pass through the porous skin surface or into oral secretions with no symptoms at all. This is called asymptomatic shedding and is of course contagious. In reality, a person may have been exposed to the cold sore virus (HSV-1) without knowing it, be shedding the virus asymptomatically, and transmitting it unknowingly to others. The literature suggests that there is approximately a 5-15% chance of asymptomatic shedding at any given time. Your doctor has a blood test that can tell if you have been exposed to the herpes virus. Many tests are specific and can tell you if you have been exposed to HSV-1 or HSV-2 or both. There are also ways to test a lesion (before it scabs) to see what species of virus is present.
What can be done to prevent Cold Sores from spreading?
The cold sore virus (HSV-1) is very sensitive to soap and warm water. If you have a lesion, the best way to help prevent spread of the virus is frequent hand washing with soap and warm water. To prevent infecting others, kissing and intimate contact should be avoided while any symptoms of an active cold sore lesion are present. Take care to avoid touching the sores and spreading the virus to new sites (auto-inoculation) or socially touching others. Another important way to help prevent the spread of cold sores is to treat the cold sore with a cold sore medicine in order to shorten the time that it is contagious.
What is the treatment for Cold Sores / Fever Blisters?
From what medical science knows to date, it is important for anyone with cold sores (or any other herpes infection) to understand that the infection is permanent. There is no cure. Finding a way to get a medicine into the cell body of sensory nerves has proven to be a challenging feat that has not yet been effectively accomplished.
If you have lesions on the lips that may be due to the cold sore virus (HSV-1), but you want to be sure, consult a doctor who will possibly take a viral culture from an infected site and a blood test to determine first the presence or absence of antibodies to HSV. (If you get lesions in other places, you should see your doctor as soon as possible.)
Some people treat their cold sores with a prescription obtained from a doctor. Others go to the drug store and buy a product over-the-counter. Some people obtain unapproved (and perhaps unsafe) products over the Internet. Some people do not treat their cold sores at all either because of cost concerns, or, because the products available to them do not work for them.
Prescription (Rx) Treatments
There are prescription drugs (Rx) for the treatment of cold sores. The currently FDA-approved prescription anti-viral drugs are known as nucleosides. They act by offering the herpes virus a defective nucleoside building block (fake DNA). The nucleoside drugs (acyclovir and drugs based on acyclovir such as Zovirax, Valtrex®, Denavir®, Famvir®, etc.) act by interfering with viral replication. For many people, these drugs decrease the incidence, duration and severity of lesions as well as decrease asymptomatic viral shedding. The effectiveness of these drugs in treating the virus is not universal. Some people report very favorable results. Others do not respond well at all. Financial considerations pose problems for still others who may not have insurance. Even though nucleosides have a good safety history, some people are leery of and fret over the theoretical long-term consequences of repeated use of oral nucleosides, especially when taken internally.
Over-The-Counter (OTC) Treatments
There are also many OTC remedies made available under FDA approvals or under special rules called monographs which are written to provide guidance to manufacturers about how to formulate and label specific products used to treat specific disease conditions over-the-counter.
There are several OTC approaches to treating cold sores. The most common of these are skin protectants. These products coat the cold sore to protect it and facilitate healing. Still other medications contain agents to temporarily numb the area so that the lesion is not as painful.
A new and innovative approach to treating cold sores involves the use of topical microbicidal products (Viroxyn®) to directly attack the infection. The use of germicides is a new and exciting approach and is being studied in the treatment of other types of infections.
Treatments Not Approved By FDA
There are also a host of medications and procedures that are not approved by FDA and may not be safe or effective. Since they have not been reviewed or studied by any regulatory or scientific body of experts, they will not be discussed here, except to say that many people are so eager to be rid of their cold sore that they will try almost anything to find some relief from the pain and social embarrassment of having a cold sore.
What do I need to remember about Cold Sores / Fever Blisters?
Cold sores are caused by the herpes virus; usually Herpes Simplex Virus Type 1 (HSV-1). There is no cure for herpes. The cold sore virus is very contagious during a lesion, but it can be present even if a cold sore is not. People with cold sores need to guard against unintentional transmission to others. This is best done by avoiding kissing of others, washing your hands frequently, and by making sure to avoid touching other parts of your body after touching your cold sore. Another useful suggestion is to treat your cold sore with a cold sore medication to reduce the time that it is contagious.
There are treatments available from your doctor or your dentist. Rx treatments act to interfere with viral reproduction and are only available with a prescription. You can also buy over-the-counter (OTC) drugs to treat your cold sore. Some OTC drugs act as skin protectants. Some have an anesthetic to reduce the pain.
A new type of cold sore treatment has recently been introduced that capitalizes on the microbicidal effects of its active ingredient (benzalkonium chloride) to directly act on the cold sore virus. This treatment is available as Viroxyn.
If you wonder what is best for you, you should ask your doctor or dentist.
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