Cold sores – NHS

Cold sores are common and usually clear up on their own within 10 days. But there are things you can do to help ease the pain.

Check if it’s a cold sore

A cold sore usually starts with a tingling, itching or burning feeling.

Over the next 48 hours:

Small fluid-filled blisters appear.

Credit:

SCIENCE SOURCE/SCIENCE PHOTO LIBRARY https://www.sciencephoto.com/media/257566/view

The blisters can appear anywhere on the face.

Credit:

PAN XUNBIN/SCIENCE PHOTO LIBRARY https://www.sciencephoto.com/media/479137/view

The blisters burst and crust over into a scab.

Credit:

C0473050, DR P. MARAZZI / SCIENCE PHOTO LIBRARY https://www. sciencephoto.com/media/1051811/view/cold-sore-on-lip

Cold sores should start to heal within 10 days, but are contagious and may be irritating or painful while they heal.

Some people find that certain things trigger a cold sore, such as another illness, sunshine or menstrual periods.

When it’s not a cold sore

How long cold sores are contagious

Cold sores are contagious from the moment you first feel tingling or other signs of a cold sore coming on to when the cold sore has completely healed.

A pharmacist can help with cold sores

A pharmacist can recommend:

• creams to ease pain and irritation
• antiviral creams to speed up healing time
• cold sore patches to protect the skin while it heals

You can buy electronic devices from pharmacies that treat cold sores with light or lasers.

Some people find these helpful, but there have not been many studies to confirm if they work.

Information:

If you regularly get cold sores, use antiviral creams as soon as you recognise the early tingling feeling. They do not always work after blisters appear.

Things you can do yourself

Cold sores take time to heal and they’re very contagious, especially when the blisters burst.

Important

Kissing a baby if you have a cold sore can lead to neonatal herpes, which is very dangerous to newborn babies.

Do

• eat cool, soft foods

• wash your hands with soap and water before and after applying cream

• avoid anything that triggers your cold sores

• use sunblock lip balm (SPF 15 or above) if you’re outside in the sun

• take paracetamol or ibuprofen to ease pain and swelling (liquid paracetamol is available for children) – do not give aspirin to children under 16

• drink plenty of fluids to avoid dehydration

Don’t

• do not kiss anyone while you have a cold sore

• do not have oral sex until your cold sore completely heals as you could give your partner genital herpes

• do not touch your cold sore (apart from applying cream) – if you do wash your hands

• do not rub cream into the cold sore – dab it on instead

• do not eat acidic or salty food if it makes your cold sore feel worse

Non-urgent advice: See a GP if:

• the cold sore has not started to heal within 10 days
• you’re worried about a cold sore or think it’s something else
• the cold sore is very large or painful
• you or your child also have swollen, painful gums and sores in the mouth (gingivostomatitis)
• you have a weakened immune system – for example, because of chemotherapy or diabetes

Treatment from a GP

A GP may prescribe antiviral tablets if your cold sores are very large, painful or keep coming back.

Newborn babies, pregnant women and people with a weakened immune system may be referred to hospital for advice or treatment.

Why cold sores come back

Cold sores are caused by a virus called herpes simplex.

Once you have the virus, it stays in your skin for the rest of your life. Sometimes it causes a cold sore.

Most people are exposed to the virus when they’re young after close skin to skin contact, such as kissing, with someone who has a cold sore.

It does not usually cause any symptoms until you’re older. You will not know if it’s in your skin unless you get a cold sore.

Page last reviewed: 20 July 2020
Next review due: 20 July 2023

Causes, Symptoms, Treatment, Complications, and Prevention

Written by WebMD Editorial Contributors

Medically Reviewed by Poonam Sachdev on May 10, 2023

• What Is a Cold Sore?
• Cold Sore Symptoms
• Cold Sore Causes
• Cold Sore Risk Factors
• Cold Sore Diagnosis
• Cold Sore Treatment
• Cold Sore Complications
• Cold Sore Prevention
• More

A cold sore is a group of tiny, painful blisters caused by the herpes simplex virus (HSV). They’re also called fever blisters or herpes simplex labialis.

Up to 90% of people around the world have at least one form of HSV.

The symptoms are usually the most serious the first you time you get cold sores. A first-time cold sore can make a child seriously ill.

After the first outbreak, your body should make antibodies, and you may never have another infection. But many people get cold sores that come back.

Cold sores, or fever blisters, are groups of small blisters on the lip and around the mouth. The skin around the blisters is often red, swollen, and sore. Photo credit: Courtesy of the CDC

Cold sores are most likely to show up on the outside of your mouth and lips, but you can also get them on your nose and cheeks.

You may get cold sores as late as 20 days after you’re infected. The sore might appear near where the virus entered your body.

Cold sores happen in stages:

1. You have a tingling, burning, or itching feeling.
2. About 12-24 hours later, blisters form. The area becomes red, swollen, and painful.
3. The blisters break open and fluid comes out. This usually lasts 2 or 3 days.
4. A scab forms on the sore. It might crack or bleed.
5. The scab falls off.

You might also have red or swollen gums, swollen glands in your neck, fever, or muscle aches.

First-time infections can also cause:

• Burning and pain inside your mouth
• Sore throat
• Pain when you swallow
• Headache
• Upset stomach

You catch HSV when you come into contact with people or things that carry the virus. For instance, you can get it from kissing someone who has the virus or from sharing eating utensils, towels, or razors.

Two types of the virus can cause cold sores: HSV-1 and HSV-2. Both types can also cause sores on your genitals and can be spread by oral sex. 

Type 1 usually causes cold sores, and type 2 mostly causes genital herpes, but either can be found in both areas.

Certain things can trigger an outbreak, including:

• Some foods
• Stress
• Fever
• Colds
• Allergies
• Fatigue
• Sunburn or being in strong sunlight
• Dental work or cosmetic surgery
• Your period

Cold sores generally aren’t serious, but the infection may be life-threatening for someone who has a weakened immune system because of AIDS, another condition, or medications. 

If you have a serious case of the skin condition eczema, you may get cold sores over large parts of your body.

Your doctor might diagnose a cold sore just by looking at the blisters. They can also swab the blister and test the fluid for HSV.

There’s no cure for cold sores. Once you have the virus, it stays in your body. The sores themselves usually heal on their own in 1 or 2 weeks.

Antiviral medications can speed healing, especially if you take them at the first sign of an outbreak. Your doctor might tell you to use:

• Cream that you apply on the sores. Acyclovir (Zovirax) and penciclovir (Denavir) require a prescription, or you can get docosanol (Abreva) over the counter.
• Pills you swallow, like acyclovir (Sitavig, Zovirax), famciclovir (Famvir), or valacyclovir (Valtrex). You need a prescription to get these.
• Medicine injected into your bloodstream (called intravenous or IV), such as cidofovir (Vistide) or foscarnet (Foscavir), if you have a serious case. Acyclovir can also be injected.

Some home remedies can help you feel better while you heal:

• Cold, damp compresses
• Over-the-counter pain medicines like acetaminophen and ibuprofen
• Cream painkillers with benzocaine or lidocaine
• Treatments with alcohol to dry out the blisters
• Lip balms and creams to keep moisture in

Complications from a cold sore are rare, but can happen if the virus spreads to another part of your body, including your:

• Fingers. This infection is called herpes whitlow.
• Genitals. You might have warts or ulcers on your genitals or anus.
• Other areas of skin. If you have eczema and get a cold sore, see your doctor right away to avoid a serious condition called eczema herpeticum. This painful rash covers large areas of skin.
• Eyes. HSV keratitis, an infection in your cornea, can cause blindness.
• Brain or spinal cord. The virus can cause dangerous inflammation called meningitis or encephalitis, especially in people who have weakened immune systems.

To lower your risk of another outbreak:

• Get plenty of rest. A lack of sleep weakens your immune system, so you get sick more easily.
• Wear lip balm with sunscreen. Look for SPF on the label.
• Talk with your doctor. If you get sores often, they might have you take an antiviral medicine every day.

To keep from spreading the virus, when you have cold sores, don’t:

• Kiss anyone
• Share eating utensils, glasses, towels, lipstick or lip balm, or razors
• Have oral sex

Keep in mind that you can spread the virus even if you don’t have symptoms.  

Top Picks

Why very hot and very cold hurt us

• Jason Goldman
• BBC Future

March 24, 2017

in events.

Copyright © iStock

Touching something very hot or very cold hurts us. Columnist BBC Future decided to figure out what is the reason for such an unpleasant sensation.

At first glance, there is nothing in common between a hot waffle iron and a block of ice. However, both of these items can cause pain to a person.

Both extreme heat and extreme cold can cause irreparable damage to human skin. It turns out that the brain perceives extremely low and high temperatures in approximately the same way.

• Are ice baths healthy?
• The mystery of people who are not affected by local anesthesia
• Why is pain pleasant?
• Why is pain so difficult to measure and relieve?

According to popular belief, the skin and the nerve endings in it are primarily responsible for touch.

However, what biologists call somatic sensations actually includes a wide range of human feelings.

Of course, this is the sense of touch itself, or recognition of mechanical stimuli by the skin, but besides it there is nociception – painful excitation of nerve fibers.

The sensation of pain is the body’s response to nociception.

Image copyright, iStock

Image caption,

Our response to cold is completely dependent on a specific protein

Whether the pain stimulus is mechanical, chemical, or thermal, nociception prompts us to immediately get rid of it.

If you put your hand near the fire, you will feel a burning sensation and immediately remove it.

The feeling is not pleasant, but in fact pain is a confirmation that your body is trying with all its might to protect you from danger. If you lose the ability to feel pain, you will face serious problems.

“The underlying principle,” says neuroscientist Joerg Grandl of Duke University, “is that sensory neurons that transmit nerve impulses to the brain have special channels that are directly activated by high or low temperatures.”

By studying genetically modified mice over the past 15 years, scientists have been able to prove that these channels, namely the proteins contained in the membranes of neurons, are directly related to the sensation of temperature.

One of them, called TRPV1, is the best studied. It reacts to very high temperatures.

Typically, TRPV1 is activated at 42°C, which both humans and mice perceive as painfully high.

As soon as the exposure to the skin reaches the specified limit, the channel is activated, and after it the entire nerve is excited, and a simple signal enters the brain: oh!

“Roughly the same mechanisms operate at low temperatures,” Grandl explains.

He adds that in the case of cold, a protein called TRPM8 is involved, and the channel is activated not at painfully low, but rather moderately low temperatures.

One more protein remains – TRPA1. Of all the proteins in this class, it is the least known.

Scientists have found that it is activated when exposed to very low temperatures, but it is not known whether it is involved in the actual process of detecting stimuli. Image credit: iStock

Since these proteins are nociceptors, their main task is not to look for certain temperatures, but to help a person avoid them.

For example, mice with a defective TRPM8 receptor are indifferent to moderately low temperatures and do not actively seek a more comfortable environment.

Scientists have determined the temperature limits at which these TRP receptors are activated, but this does not mean that they cannot vary.

After all, if you’re sunburnt, even a lukewarm shower can cause you unbearable pain.

“This has been shown to be due to skin inflammation activating the TRPV1 channel,” Grandl says.

As a result, the threshold at which these nerves transmit a pain signal to the brain is reduced.

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These receptors are activated not only by exposure to temperatures, but also by contact with the skin of certain plants.

It may not come as a surprise to you that the TRPV1 receptor, which is activated by extreme heat, also responds to capsaicin, the hot pepper substance.

TRPM8 is sensitive to the cooling properties of menthol, a substance found in mint leaves, and TRPA1 is also called the “wasabi receptor” because it is activated by contact with irritants found in mustard plants.

Why do plants produce substances that act on our receptors, which are usually activated by temperature changes?

Molecular biologist Ajay Daka of the University of Washington explains that capsaicin has no effect on TRPV1 in fish, birds, and rabbits, while it activates the same receptor in humans and rodents.

“Perhaps the plants started producing capsaicin to stop certain animals from eating them,” he says, adding that other animals would still eat them.

Similar mechanisms are thought to have influenced the evolution of mint and mustard.

Image copyright, iStock

Image caption

Heat-responsive TRPV1 is also activated by contact with capsaicin found in chili peppers

Plants may have been able to take advantage of our body’s ability to recognize temperatures by accident.

That is why they could begin to secrete substances that activate receptors responsible for pain when exposed to high and low temperatures.

So the fact that we sweat when we eat jalapeno peppers is not related to the properties of the pepper itself. Rather, this is a consequence of the fact that both capsaicin and heat have the same effect on the nerve endings of the skin and, therefore, on the body as a whole.

Taking advantage of a receptor already tuned in to unpleasant stimuli, these plants have found a clever way to avoid a sad fate – at least until we began to enjoy the burning spicy food and the tear-filling taste of wasabi.

The next time your heart is racing after chili, think about how you feel is the result of millions of years of evolutionary struggle between plants and animals.

The struggle that we – at least for today – are winning.

Read the original of this article in English at BBC Future .

how to keep women’s health in winter?

Cold and inflammation: how to keep women’s health in winter?

• CLINIC21
• News and articles
• Cold and inflammation: how to keep women’s health in winter?

February 13, 2020

This year, winter “pleases” us with very unstable weather: it will either freeze, then thaw again. In such weather, women, especially young ones, tend to dress lightly and wear thin tights. But the thaw in winter is very insidious, and light clothing provokes the development of inflammatory diseases of the pelvic organs.

Danger of cold for women’s health

The danger of inflammatory diseases is due to the fact that a woman does not immediately pay attention to the symptoms or refers them to a completely different area of ​​the body. The symptom may be lower back pain, which is associated with neurological disease, or frequent and painful urination, indicating cystitis. But it can also be symptoms of gynecological inflammatory diseases.

In the cold season, you should be very attentive to any manifestations of abnormalities in your body, you should definitely consult a gynecologist if you feel:

• pain in the lower abdomen, sometimes radiating to the lower back;

• increased secretions from the genital tract;

• change in the nature of the discharge;

• pain during menstruation or during sexual intercourse;

• frequent and/or painful urination;

• change in the nature of menstruation and / or intermenstrual bleeding.

“Women’s” diseases are especially dangerous complications. Self-medication can lead to the transition of inflammation into a chronic process, so it is more correct to seek help and complete a full course of anti-inflammatory treatment. We remind you that prevention is better than cure.

What to do if you are cold? Opinion of a gynecologist

Obstetrician-gynecologist at CLINIC21 Fedorova Olga Arkadievna recommends:

“In the cold season, wear clothes that are appropriate for the weather and the season. If suddenly you are cold, your feet are wet, then you can take a warm bath or make a hot foot bath, change into warm and dry clothes, drink warm tea (preferably herbal) and take any remedy from the NSAID group (non-steroidal anti-inflammatory drugs).

Appointment with a gynecologist

If you feel discomfort or pain in the intimate area, then make an appointment with a gynecologist. An examination by a doctor will allow timely detection of an inflammatory disease and start treatment.

Please note that a gynecologist should make a diagnosis and prescribe a treatment regimen. Properly selected drugs and methods will relieve acute symptoms of the disease and help prevent complications.