Cold sore identification

Cold sore identification DEFAULT

Stages of cold sore development: What to know

Cold sores, also known as herpes labialis, are caused by nongenital herpes simplex virus type 1. People can develop a cold sore on their lips or in their mouth.

Transmission of the nongenital herpes simplex virus type 1 (HSV-1) occurs during childhood through nonsexual contact, but adults can contract the infection through sexual activity. HSV-1 hibernates inside skin cells and neurons under the skin until a trigger stimulates it.

Before the cold sore appears, people may feel a burning, stinging, or itching sensation on their lips. For best results, doctors recommend starting treatment as soon as the tingling begins, before the cold sore appears.

In this article, we discuss the stages of a cold sore and what to do if a cold sore develops. We also explore how doctors treat the infection and how people can avoid getting a cold sore.

Stages of a cold sore

A cold sore develops in five stages and will typically last between 9 and 12 days.

an infographic showing the stages of a cold saw

Stage 1

Initially, people will feel a tingling, itching, or burning sensation underneath the skin around the mouth or base of the nose. Doctors call this the prodrome stage.

Other that may occur during this stage include:

  • malaise
  • fever
  • tender or swollen lymph nodes

At this first stage of the cold sore, people will not see a blister. People with recurring cold sores may present milder symptoms. Doctors recommend starting treatment as soon as these symptoms begin.

Treatment for cold sores may include oral or topical medications. Sometimes people will use both types to treat a cold sore.

Oral medications for cold sores include:

  • acyclovir (Zovirax)
  • famciclovir (Famvir)
  • valacyclovir (Valtrex)

Topical treatments for cold sores include:

  • acyclovir (Zovirax) cream
  • docosanol (Abreva)
  • penciclovir (Denavir) cream

Treatment aims to shorten the duration of the cold sore. In published in Antimicrobial Agents and Chemotherapy, researchers found that high doses and short courses of valacyclovir may reduce the duration of a cold sore by about 1 day.

Taking medication when symptoms first appear can prevent or block the cold sore from appearing.

Stage 2

If the person does not use any medication, a fluid-filled blister will likely develop around 1 to 2 days after the initial symptoms.

Stage 3

The third stage, which occurs around day 4, involves the blister opening up and releasing its fluid. Doctors call this stage the ulcer or weeping stage. If another person comes into contact with the blister’s fluid, they may develop a cold sore as well.

Cold sores are contagious and tend to be painful during this stage.

Stage 4

Between days 5 and 8, the cold sore will dry up, leaving a yellow or brown crust. The crust will eventually flake off.

People must take care of the scab during this stage because it can crack or break.

Stage 5

The final stage of a cold sore is the healing stage.

Several scabs may form and flake off during this stage. Every new scab will be smaller and smaller until the wound heals completely. Most often, the cold sore will not leave a scar.

Some doctors suggest that a cold sore can last around .

Causes and risk factors

People who come into contact with another person’s cold sore may be at risk of infection. However, they would have to come into contact with the fluid when the blister ruptures.

Some people may develop recurring cold sores. According to the American Family Physician (AAP), various stimuli can awaken the hibernating virus, such as:

  • stress
  • fever
  • sun exposure
  • extremes in temperature
  • ultraviolet radiation
  • a compromised immune system
  • injury

Are they contagious?

When a cold sore enters the ulcer or weeping stage, around the fourth day, the cold sore becomes contagious.

People who come into contact with the fluid from another person’s open blister can develop a cold sore between 2 to 20 days after contact.

People can come into contact with fluid from another person’s cold sore through kissing or sharing utensils, drinkware, cosmetics, or towels.


Doctors suggest that treating a cold sore at the start of symptoms, before the blister appears, may prevent the cold sore from appearing.

People with a history of cold sores can usually detect the initial symptoms and know they need to start treatment right away.

Some people get chronic cold sores and may require preventive treatments. Taking acyclovir or valacyclovir every day may prevent cold sores.

According to the AAP, the recommended doses for each drug are:

  • acyclovir 400 milligrams (mg), twice daily
  • valacyclovir 500 mg, once daily

People with chronic cold sores will need to take preventive treatments regularly. Also, doctors and dentists recommend:

  • eating foods high in lysine, such as red meats, fish, and dairy
  • applying sunscreen to the face and lips before going outside throughout the year
  • shaving with a disposable razor blade when a cold sore appears
  • replacing toothbrushes
  • avoiding stress

People should avoid intimate contact with people who have cold sores. Avoid sharing utensils, toothbrushes, towels, and razors.

People with cold sores should avoid touching the blister, and if they do, they need to wash their hands thoroughly.


Cold sores are a common infection of nongenital HSV-1 that people can contract through sexual and nonsexual activities.

People who start treatment when they feel tingling and itching around their lips may block the cold sore from appearing.

If a cold sore appears, it will go through five stages from the prodrome stage to healing. During the ulcer stage, people can transmit the virus to another person. The fluid in the blister contains the virus. People with cold sores must avoid kissing and sharing utensils, towels, and drinkware.

A person may have a cold sore for about 2 weeks, but some doctors suggest that a cold sore can last up to 6 weeks. Medications can help shorten the duration of a cold sore.


Cold sore stages

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Is it a cold sore or a canker sore?

Cold sores are a cluster of blisters that first appear clear then become cloudy. First infection may be inside the mouth, but cold sores generally appear outside the mouth on the lips.

Canker sores are gray or white sores surrounded by a red inflamed area. They occur only inside the mouth, on the tongue or the insides of the cheeks, lips or throat.

What are cold sores?

Despite their name, cold sores (also known as fever blisters) are not caused by the common cold. Cold sores typically result from a viral infection called herpes simplex virus (HSV).

Cold sore blisters can occur on many different parts of the body but are most common on or around the lips, cheeks, or nose and also (on rare occasions) in the eye.

Symptoms of the initial infection are similar to those of other viral infections and may include fever, swollen glands, fatigue and multiple sores in the mouth and on the gums.

Recurrences are less severe and the individual may notice a burning or tingling sensation 24-48 hours before a cluster of blisters appear. These small fluid-filled blisters then become cloudy and pus-filled. After the blisters have broken to reveal a bright red area, they dry up, crust and heal within 7-10 days. Painful sores in or around the mouth may make eating difficult.

Symptoms subside after the initial illness runs its course, but the virus remains in the nerve cells until reactivated. Once reactivated, HSV travels down the nerve cells into the skin, causing its characteristic fever blisters typically in the same location. Most people with recurrent cold sores cannot recall having had the first infection; they may have been too young to remember or the infection may have been very mild. Some infected individuals never develop cold sores because the HSV is never reactivated; however, others may experience recurring sores several times a year.

Causes:  Herpes simplex virus (HSV) typically causes cold sores. HSV is very common. It has been estimated that nearly 50% of children entering kindergarten and 90% of adults have been infected with HSV, although a much smaller percentage has experienced symptoms.

Two types of HSV: have traditionally been differentiated by location. HSV-1 generally occurs above the waist (e.g., a cold sore on the lip). HSV-2 generally occurs below the waist (e.g., sexually transmitted sores on the genital area). However, it is possible to have a HSV-1 infection below the waist and vice versa. For example, HSV-1 infection can be transmitted from mouth to genitals during oral sexual contact. Both strains have similar signs, symptoms and course of disease, and both are contagious so contact should be avoided.

A number of factors can trigger the HSV virus, including sunlight, sunburn, stress, fatigue, other infections, fever, menstruation and intestinal upset. In many cases, the precipitating factor is unknown. Identifying triggers may allow a person to prevent recurrences by effectively removing these factors. For instance, if exposure to sunlight usually precedes cold sores by 24-48 hours, one can be fairly confident that sunlight is a "trigger" and one should minimize exposure.

Treatment: There is no cure for cold sores. However, some medications may relieve pain and soften HSV crusts on the skin. These remedies include:

  • Denavir (pencyclovir cream), a topical antiviral cream recently cleared for marketing by the FDA that may decrease the duration of lesion pain and accelerate healing.
  • Acyclovir (Zovirax) or valacyclovir (Valtrex), taken orally, may decrease symptoms if started within 24-48 hours after the onset of symptoms. With topical ointments, there is no demonstrated proof of effectiveness with recurrences.
  • A moistened styptic pencil used several times a day.
  • Zinc oxide ointment used after crusts have formed.
  • A drying agent (e.g., 70% rubbing alcohol or Blistex ointment) particularly when sores first appear.

Note: It is not recommended to use steroid ointments, dye-light therapy, smallpox vaccination or vitamin therapy (unless a deficiency exists). These techniques are ineffective and may actually make the sores worse.

Transmission and prevention:  HSV is contagious and may be transmitted by any contact with the blisters until the sore is healed. Furthermore, most people with HSV shed the virus and may be infectious even when sores are not present. Asymptomatic shedding from the site where sores appeared may occur randomly up to 3-6 days or more each year.

Therefore, people with oral HSV who are sexually active should use condoms or latex barriers with every oral sexual encounter. Spreading the cold sore to another site on your own body is not common; however, washing hands after touching any sore is reasonable precaution, and one should be especially wary of spreading the virus to the eyes.

When to seek medical care: Consult a clinician if:

  • Cold sores become infected with bacteria (draining pus)
  • Cold sores do not go away after a couple of weeks
  • You develop a temperature over 100° F
  • You experience eye irritation

What are canker sores?

Canker sores (aphthous ulcers) are painful sores inside the mouth. Canker sores are twice as common in women and usually first appear between the ages of ten and twenty although they may appear as early as age two.

Symptoms:  Although canker sores can appear anywhere on the mucous membranes of the mouth, they most frequently appear on the inner surfaces of the cheeks and lips, tongue and soft palate.

They are usually oval or round with a grayish-white eroded surface surrounded by a red inflamed area. The sores may occur singly or in groups and vary from about 1/8 inch to 1 -1/4 inch in diameter.

The sore may be painful for three or four days, but complete healing usually takes ten to fifteen days. Canker sores may recur many times each year.

Causes:   No one knows what causes canker sores. They may be caused by a virus, may be a form of allergic reaction or may result from an auto-immune condition (meaning that the body has developed an immune reaction against its own tissue). Some people have also found eating citrus fruit and other acidic foods increase the occurrence of canker sores, but this has not been scientifically proven.

Factors that may trigger these sores (without actually causing them) are injury or irritation (e.g., from dentures or sharp teeth), smoking, stress, a diet lacking in vitamin B12, folic acid or iron and the onset of menstruation for some women.

Treatment:  Nothing cures canker sores or prevents recurrence. There are, however, ways to ease discomfort during the 3-4 days when the sores are painful and also prevent infection.

To prevent discomfort, try to avoid irritation of abrasive or spicy foods and use care not to irritate the sore while brushing your teeth. A gel such as benozocaine can also be used to numb the sore and ease the pain.

Cleansing antiseptic medications may prevent infection and promote healing. These medications can be used as rinses or gargles 3-4 times a day or as directed on the label. Many antiseptic and pain-relief medications may be purchased without a prescription. A few examples are:

  • Hydrogen peroxide diluted with water to half-strength
  • One tablespoon of salt and baking soda in four ounces of water
  • Glyoxide (a non-prescription product)
  • Wet tea bags held over the area

Vitamins may help in cases where a specific deficiency exists. In a study at the National Institute of Dental Research, half of the people with iron, folic acid or vitamin B12 deficiencies responded favorably to supplementation while the other half showed no response.

If you experience canker sores very frequently, it may be helpful to get tested for allergies, because avoiding certain foods may minimize canker sores due to food allergies.

When to seek medical care:  Consult a clinician if:

  • Your canker sores are so severe that eating is difficult
  • You experience canker sores very frequently

For more information:

Schedule an Appointment: Appointments are required for most medical services, however options are available for urgent concerns.

Nurse Advice by Phone is available day and night, which may save a trip to UHS, the ER or an urgent care facility.

The UHS Pharmacy carries most of the treatments mentioned, and pharmacists are available for consultation.

Is That Red Lip Bump a Cold Sore or Something Else?

If you've ever had a pimple pop up in close vicinity to your mouth, chances are you've wondered — even if just for a millisecond — if said blemish could actually be a cold sore, also known as oral herpes. It's not an outlandish thought to have, either. Pimples and cold sores share certain similarities (especially in terms of appearance), which could easily elicit some confusion in someone who's suffering a breakout.

In actuality, pimples and cold sores on the lips share very little in common, making them pretty easy to distinguish from one another once you know what to look for. With that in mind, Allure tapped several dermatologists to find out the differences between pimples and cold sores, what exactly makes them so different from one another, and of course, how you can treat them should they arise. Scroll down for the lowdown.

What causes a cold sore?

Cold sores are caused by the herpes simplex virus-1, also called oral herpes or HSV-1, and they are contagious. The majority of people are exposed to the virus during childhood, but only 30 percent of people actually get clinical cold sores, says Friedman. You can catch the virus through direct skin contact, for example kissing or even using the same cup as someone with an active sore. From there, the virus pops out when your immune system is compromised or worn down, typically during times of emotional or physical stress, or if you're sick, explains Zeichner.

As most of us know, acne can also occur during times of stress, but that's where the similarities come to a halt. "Pimples can develop when hair follicles get infected with bacteria or fungus or blocked with a plug composed of oil, dead skin cells, and potentially other debris resulting in inflammation and bacterial overgrowth," says Shah. Friedman adds that all acne is inflammatory, and when inflammation brews around the sebaceous gland, it causes the area to swell and more sebum to be produced, ultimately resulting in what usually appears as a pus-filled pimple. Those with hormonal acne also experience pimples, most often around the jawline area, during their menstrual cycle or when their hormones are fluctuating. Such is not the case in cold sores, as it's a viral infection not impacted by hormones.

What are the early cold sore symptoms?

The simplest way to determine whether you have a pimple or a cold sore is to pay close attention to the warning signs. For instance, if you feel a tingling or burning sensation before the blemish even emerges, that's your body's way of telling you a cold sore is coming. "Often you may notice tingling, itching, or burning in the area before the blisters appear," explains Sejal Shah, a New York City-based dermatologist. This is known as the prodromal phase in the herpes simplex virus, which is when people experience changes in themselves (such as said burning) but haven't yet acquired any clear-cut symptoms.


Identification cold sore

Do I Have Herpes? Cold Sores 101

Posted on June 13th, 2019

Cold sore. Fever blister. Herpes Simplex Virus-1. These babies go by a lot of different names, but the experience is always the same:

  • Telltale burning or itching near the lip
  • A red bump appears a day or so later
  • Bump becomes a cluster of blisters
  • Blisters dry up and scab over
  • The scab falls off
  • The whole process usually takes two weeks or less.

Infamous for irritating pain and ruining first dates everywhere, cold sores sure wreak a lot of havoc for something so small.

A cold sore is a symptom of the herpes simplex virus-1 (HSV-1) in your system. HSV-1 is so common that most people are exposed to it in childhood. Many people can have and spread the virus without ever actually having a cold sore.

Catching & Spreading a Cold Sore

Sadly, once you catch HSV-1, there is no permanent cure. Thankfully, it won’t do much harm. If you have HSV-1, you might occasionally experience cold sores with long periods between each outbreak. This is because HSV-1 has the habit of “sleeping” or being inactive for bouts of time before circumstances cause it to flare up.

If you get cold sores, anything that compromises your immune system will make you susceptible to an outbreak. This includes drinking too much alcohol, stress, lack of sleep, or being sick. Even overexposure to the sun can cause a cold sore flare.

HSV-1 is related to the same virus that causes the herpes STD: HSV-2. Both viruses can be passed via bodily fluids, but HSV-1 cold sores usually only appear around the mouth.

HSV-1 is extremely contagious and can be spread even without a visible cold sore. Washing hands and a large personal bubble are important to prevent spreading or catching cold sores. Don’t share cups, utensils, lip balm, or razors if you or someone you know has a cold sore.

Don’t worry about catching cold sores from the dentist. All rooms and equipment are thoroughly sanitized between each patient.

Cold Sores vs. Canker Sores

If you have a mouth sore, you might be wondering if it’s a cold sore or a canker sore (which is not contagious). There are two main ways you can tell the difference between the two: location and appearance.

Cold sores are mostly outside the mouth on the lips or nose, and canker sores are mostly inside the mouth. Cold sores are usually a group of red blisters. Canker sores are round, open sores with a yellow or gray center.

Cold sores might also cause fever, sore throat, and swollen lymph nodes.

Treating Cold Sores

Skin creams and gels can help ease the pain of cold sores and make them go away faster. Talk with your dentist and doctor if you want help fighting the effects of a cold sore. Long-term treatment may also help reduce the frequency and severity of your outbreaks.

Drs. Nozik and Tumminelli are taking new patients and would love to help you love your smile! Make an appointment with us today if you have questions about cold sores or any other oral health issue.

The content of this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.





Mayo Clinic Minute: 3 things you didn't know about cold sores

Cold sores / Fever blisters – Stages | Identification | Pictures | Signs & Symptoms.

– Are cold sores contagious? / How is the herpes virus spread? / When is transmission most likely?

Link to cold sore stages slideshow.
Link to cold sore locations slideshow.

Cold sores (fever blisters) are usually distinguished from other types of mouth sores by way of evaluating:

  1. The way the sore looks as it goes through its stages of formation.
  2. The location in which the lesion forms.
  3. Laboratory testing can be performed but is not commonly used or needed.


(Scroll on down this page for pictures and details.)

A) What do cold sores look like? (The 5 stages.)

The appearance of a cold sore (fever blister) will gradually change as it progresses through the five stages of formation outlined below.

The timeline for this transformation (from the first sign to complete healing) usually lasts between 8 and 12 days.

FYI: The stage of your sore correlates with its level of contagiousness.

1) The Tingle stage (Prodrome stage) – days 1 & 2.

In most cases, a person’s first indication that they have a cold sore starting to form is that they notice a new sensation (burning, stinging, itching, soreness, tautness, or swelling) in the area where the lesion will ultimately appear.

What to look for – The area may become reddened, and slightly raised or elevated (papule formation).

Things to know – All of these initial symptoms are signs of inflammation. (Your body’s response to the herpes virus and the tissue damage it’s starting to cause.)

Slideshow showing pictures of the stages of cold sore formation.

The stages of cold sore (fever blister) formation.

2) The Blister stage – days 2 & 3.

The first readily visible sign of cold sore formation is the appearance of multiple fluid-filled blisters.
What to look for – The blisters are usually very tiny (smaller across than the thickness of a dime). And form in a cluster that’s no larger than about the size of a nickel. In some cases, individual blisters may join together to form a single larger one.

Things to know – This is the stage where the total number herpes virions (virus particles, HSV) is the greatest. The overall size of the forming lesion generally correlates with the relative number of virions present. (Hull)

In about 25% of cases, the herpes infection is brought under control (either just by your body’s immune system or with the help of antiviral medication Details) before blisters can develop. Since no blisters or following ulceration form, these are sometimes referred to as “failed” or “aborted” lesions. (Opstelten)

▲Section references – Hull, Opstelten

3) The Weeping stage (Ulcer stage) – day 4.

The blisters usually rupture soon after they’ve appeared. As they do, they release a clear fluid teeming with herpes virions. After all have broken, the sore transforms into an area of ulceration.

What to look for – Immediately after blister rupture, the lesion starts off as a shallow red ulcer (a wet, raw-looking sore) whose surface then turns grey.

Things to know – This phase of fever blister formation can be the most painful stage, and the one during which it’s most contagious.

By this point, the replication rate of the virus has passed its peak. And the inflammation reaction triggered by the presence of the virions and damage to skin cells they have caused is in full swing as it continues to clean up the carnage. It’s this inflammation response (a part of the normal healing process) that’s responsible for redness, swelling and tenderness associated with cold sores as they continue through their stages.

4) The Crusting stage – days 5 through 8.

If the ulcer has formed in a location where it’s not kept wet by moisture from the mouth, it will scab over.

What to look for – The scabbing looks like a yellow, or dark red to brownish, crust. It often cracks or breaks, which results in bleeding.

During times when a scab has come off, you can see the amount of ulceration that still remains and the pink, newly formed tissue that surrounds it.

Things to know – The formation of the scab is often accompanied by an itching or burning sensation. Moisturizing the scab Details can help to prevent this.

5) The Final Healing stage – days 9 through 12.

As time progresses, so will the sore’s healing.

What to look for – A series of scabs will usually form on the lesion with each one flaking off before it’s replaced by a new one.

Each new scab will be smaller than the previous one, until finally the lesion resolves fully and in most cases without scarring.

Slideshow showing pictures of the locations where cold sores form.

Locations where cold sores (fever blisters) form.

B) Where do cold sores form?

  • On or at the edge of the lip.
  • On the face, near the mouth. – Such as on the chin, lower portion of the nose, or cheeks.

This is an important characteristic that aids in the identification of recurring facial lesions as cold sores.

C) Are cold sores contagious?

Yes, during times when you have a cold sore, your potential for spreading the herpes virus should be one of your concerns.

Contact with your sore, or the fluids coming from it, or even your own infected saliva can transfer herpes virions to others, or even other parts of your own body (see below).

1) Transmission to others.

a) Direct contact.

It’s generally considered that the dominant transmission route of the herpes simplex virus involves making direct contact with the infected individual, usually via one of the following events.

  • Coming into contact with the person’s herpetic lesion (direct oral skin-to-skin contact).

    The transmission event could be an activity like kissing, or even just brushing your lips against someone’s sore during a hug.

    As a best practice, if you have a cold sore, you should refrain from being intimate with others or participating in contact activities (e.g. wrestling, basketball, etc…). (See below for which cold sore stages tend to release the most virus particles.)

  • Being exposed to another person’s infected body fluids (saliva).

    While a cold sore’s level of virus replication waxes and wanes as it progresses through the stages discussed above (see additional discussion below), one must assume that any time they have a lesion that some level of virions are likely to exist in their saliva, thus making it a potential means of transmission.


  • Asymptomatic viral shedding.

    Asymptomatic shedding (periods when an infected person has no active lesion but their body sheds viral particles, such as into their saliva) may be responsible for transmission in a low percentage of cases. But as of yet, the exact degree to which this phenomenon actually plays a role in oral HSV transmission is not well documented.

    A study that monitored healthy herpes positive (HSV 1) subjects detected asymptomatic oral shedding on 12% of days, with an average duration of 24 hours for each episode (Mertz). It’s estimated that 70% of the general population sheds HSV 1 asymptomatically at least once a month (Neville).


b) Via an intermediary.

The oral pathology textbook by Regezi states: “the spread of infection through airborne
droplets, contaminated water, or contact with inanimate objects is generally undocumented.” (Our research of this subject ran across numerous studies stemming from the 1980s and 1990s that in their day had postulated these as transmission routes.)

This same opinion seems to be supported by the other reference sources we’ve used for this page, all of which portray the dominant route of transmission of oral herpes as being either infected saliva or contact with active lesions, as opposed to intermediary objects.

c) Further considerations.
A paper by Ayoub mentions the transmission of HSV 1 via shared eating habits (both utensils and food). One would have to assume that this type of activity is just another way of generating contact with an infected person’s saliva (and therefore the virions it contains). In light of this, other activities that create this same potential should be kept in mind and avoided.

▲Section references – Mertz, Neville, Regezi, Arduino, Ayoub

2) Transfer to other body parts.

Hand washing graphic.

Always wash your hands after touching a cold sore.

Besides just infections associated with the mouth, it’s important to be aware of the fact that the herpes virus can also cause infections in other body locations too. (This doesn’t just apply to other people but also includes your own body.)
  • Herpes simplex can cause herpetic whitlow, a painful infection of the fingers.
  • A herpesvirus infection of the eye can result in corneal blindness.

    (If you wear disposable contact lenses and their contamination is suspected (like by handling them after touching a sore), then throw them away. To avoid this issue, you may choose to wear your glasses when you have a cold sore.)

  • Being intimate with others can cause infection of your partner’s genitals.


3) Other best practices for preventing viral spread.

  • Don’t touch or pick at cold sores. Only touch them when treating them.
  • Dab medication on a lesion rather than rubbing it in, so not to disturb the sore.
  • Wash your hands (soap and water) after treating a lesion. And washing them repeatedly throughout the day makes a good practice too.


When are cold sores the most contagious?

Virus particles are present during all stages of cold sore formation. And for that reason, each and every stage should be considered to be contagious.

a) Wet lesions are the worst.

The most contagious stage of a cold sore is when its blisters rupture (the Weeping stage). This is because the liquid contained in these blisters holds literally millions of herpes simplex virions.

b) Scabbed lesions, less so.

As a cold sore continues to run its course, the number of virus particles present in it diminishes. Usually, by the time a scab has formed (the Crusting stage) the number of virus particles has lessened dramatically.

Concerns with at-risk persons.

Some people are at greater risk for herpetic infections and associated complications than others. And for this reason, they should be given special consideration.

This includes people with immature immune systems (newborn babies) or compromised ones (such as chemotherapy or HIV patients).

All of the basic precautions used to prevent the spread of the herpes virus need to be vigilantly practiced when these types of individuals are involved. Parents/caretakers need to establish rules about what type of contact is allowed with those in their charge.

Statistics involving newborns.

Herpes infections involving newborn children can be a serious matter, with possibly multiple organ systems being affected, and even risk of the infection causing death.

In the vast majority of cases (90%), the virus is passed to the child from their mother during delivery (whether or not she currently has any signs or symptoms of infection). Fortunately, a newborn’s risk of experiencing a herpetic infection is a low-percentage event (involving far less than 1% of newborns), and usually a manageable condition when treated (however 60% of untreated cases result in death).

In about 10% of the less than 1% of cases that do occur (making this a rare-but-possible scenario), the newborn’s resulting infection is a result of virus particles spread from another individual (sibling, grandparent, etc…), like during a kiss or other activity that brings the child into contact with the infected person’s lesion or saliva.

▲Section references – Rettner

 Page references sources: 

Arduino PG, et al. Herpes Simplex Virus Type 1 infection: Overview on relevant clinico-pathological features.

Ayoub HH, et al. Characterizing the transitioning epidemiology of herpes simplex virus type 1 in the USA: model-based predictions.

Hull CM, et al. Novel Composite Efficacy Measure To Demonstrate the Rationale and Efficacy of Combination Antiviral–Anti-Inflammatory Treatment for Recurrent Herpes Simplex Labialis.

Rettner R. Deadly Kiss: Can a Baby Contract a Lethal Virus from a Cold Sore?

Mertz G. Asymptomatic Shedding of Herpes Simplex Virus 1 and 2: Implications for Prevention of Transmission.

Neville BW, et al. Oral and Maxillofacial Pathology. Chapter: Viral Infections.

Opstelten W, et al. Treatment and prevention of herpes labialis.

Regezi JA, et al. Oral Pathology: Clinical Pathologic Correlations. Chapter: Vesiculobullous Diseases.

All reference sources for topic Cold Sores.


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Cold Sore Stages: What Can I Do?

How cold sores develop

Cold cores, or fever blisters, are caused by a form of the herpes simplex virus (HSV-1 or HSV-2). The herpes virus causes a lifelong infection that can be dormant in your body for years before causing a cold sore to appear.

Although cold sores typically form on or in your mouth, they can also develop on your cheeks, nose, and eyes.

Once you’re exposed to the virus, something generally triggers the reoccurrence of sores. Possible triggers include:

  • stress
  • fatigue
  • illness
  • hormone fluctuations
  • food allergies
  • sun exposure

Up to 90 percent of adults have HSV. As many as 50 percent of people develop the condition by the time they’re in kindergarten. Not everyone will experience the symptomatic cold sores, though.

When cold sores do appear, they typically follow the same five stages:

  • tingling
  • blistering
  • weeping
  • crusting
  • healing

Keep reading to learn what happens in each stage and how to find relief.

Stage 1: Tingling

If you feel an unexplained tingling around your mouth, you may have a cold sore coming on. Tingling is usually one of the first signs that a cold sore is about to develop on the surface of the skin. The area may also burn or itch.

Treating a cold sore during the tingling phase may reduce its severity and duration, but it won’t prevent the sore from forming. Oral medication is most useful during this phase. The medication can also be used daily to prevent or limit outbreaks.

If you develop cold sores only every once in a while, you may find topical treatments beneficial. Some of these topical treatments include:

However, some suggests these ointments can’t adequately reach the virus. So their effectiveness may be limited. A recent shows that in the lab, aloe vera gel had virus-blocking activity against HSV. This may mean aloe vera may also be an effective topical treatment.

If you have frequent cold sores or would rather take oral medication, talk to your doctor. They may prescribe one of the following:

If this stage of the cold sore is painful or bothersome, you can take OTC pain relievers like acetaminophen (Tylenol) or ibuprofen (Advil). Creams with lidocaine or benzocaine may also provide relief.

Learn the difference: Pimple vs. cold sore »

Stage 2: Blistering

About a day or two after you feel the initial tingling phase, your cold sore will typically move to the blistering phase. This is when one or more blisters filled with clear fluid appear on the surface of the skin. The skin around and under the blisters will be red. The blisters may appear on your mouth or inside of it, including in your throat.

You may already be using a pain reliever, oral medication, or topical cream to alleviate the cold sore symptoms. In addition to these treatments, you should also increase your water intake. It’s important to stay hydrated especially when your mouth is sore.

Once cold sores appear on the surface of your skin, they can easily spread. Wash your hands with warm, soapy water after you touch the affected area, and avoid sharing food or drink during this time. Kissing and oral sex can also spread the virus, so use caution. You should limit intimate contact until the blisters are completely gone.

Blisters and the stages following them may cause discomfort during eating, as well. You should avoid certain foods, such as:

  • citrus
  • spicy foods
  • salty foods
  • hot liquids

Stage 3: Weeping

The cold sore will break open, often within a few days of appearing on the surface of your skin. Open sores will be red and shallow. They are most contagious during this time.

If you haven’t already, consider using a topical or oral pain reliever to help ease your symptoms. You may also use a cold or warm compress.

Avoid picking at the sores. Picking can cause the condition to worsen or spread. It can also create a bacterial skin infection.

Stage 4: Crusting

After the weeping stage, your blister will dry. This begins the crusting stage. When the blister dries out, it will look yellow or brown. You should be careful to not aggravate the crusted blister.

Using cold and warm compresses and zinc oxide ointment may help at this stage.

Stage 5: Healing

The final stage of the cold sore is the healing stage. This is when the crusted blister scabs over. To keep the scab soft and to reduce irritation, try using emollients containing zinc oxide or aloe vera.

The scab will slowly disappear by flaking away. Cold sores generally don’t leave scars.

When to see a doctor

If you experience cold sores only on occasion, home treatment may be enough to minimize discomfort and speed up the healing process. But if you have regular cold sores, you should see your doctor for prescription medication. It may help limit the frequency and severity of your sores. Using lip balm with an added sunscreen is important as well.

You should also see your doctor if a cold sore:

  • spreads to your eye
  • is accompanied by a fever
  • doesn’t clear within a week or two
  • is surrounded by crusted or oozing skin

The bottom line

HSV is most contagious when cold sores are open and unhealed. However, the virus may also be contagious before or after the sores appear.

It’s best to take careful precautions when you experience cold sores:

  • Avoid sharing utensils and hygiene products.
  • Avoid physical contact with another person while the sores are present.
  • Don’t share products you use to treat the cold sores.
  • Wash your hands after treating a cold sore.

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