Impetigo vs cold sore

What is impetigo and what does it look like?

Impetigo is a skin infection. It is usually caused by a germ (bacterium). Often, one of the following three types of bacterial infection is responsible:

  • Staphylococcus aureus (the most common cause).
  • Streptococcus pyogenes.
  • Meticillin-resistant Staphylococcus aureus (MRSA). This is a newer type of bacterium which has become resistant to many antibiotics.

Impetigo may be classed as primary or secondary:

  • In primary impetigo, the infection affects healthy skin.
  • In secondary impetigo, the infection affects skin that is already ‘broken’ by another skin condition. For example, skin with eczema, psoriasis or a cut sometimes develops a secondary impetigo.

It can also be classed as bullous type, non-bullous type or ecthyma.

Non-bullous impetigo

This is the most common form of impetigo. The rash typically appears 4-10 days after you have been infected with bacteria. Small fluid-filled blisters develop at first. You may not see the blisters, as they usually burst to leave scabby patches on the skin. Sometimes only one or two patches develop. They often look like moist, golden crusts (like cornflakes) stuck on to the skin. An area of redness (inflammation) may develop under each patch. Sometimes affected skin is just red and inflamed – especially if the ‘crust’ is picked or scratched off.

The face is the one of the commonest parts of the body affected but impetigo can occur on any area of the skin. Patches of impetigo vary in size but are usually quite small – a centimetre or so to begin with. Impetigo can spread. Smaller ‘satellite’ patches may develop around an existing patch and spread outwards.

Facial impetigo on cheek

This type of impetigo tends to look like larger blisters. The skin on the top of these blisters is very thin and peels off, leaving large red raw areas underneath. It may occur on your face, arms, legs, or bottom. It is more likely in areas which already have another skin condition, such as eczema.

Bullous impetigo on leg

This is a more uncommon type of impetigo where the breaks in the skin are quite deep, forming ulcers.

Who gets impetigo?

Impetigo commonly occurs in children, but it can affect anyone at any age. It occurs more commonly in warm humid weather. It is contagious, which means it can be passed on by touching. Sometimes outbreaks occur in families or in people who live in close communities, such as army barracks.

You are more prone to develop impetigo if you have diabetes or if you have a poor immune system (for example, if you are having chemotherapy).

What is the treatment for impetigo?

There is a good chance that impetigo will clear without treatment after 2-3 weeks. However, treatment is usually advised as it is contagious, and severe infection sometimes develops.

A medication called fusidic acid, in the form of an antibiotic cream used for five days, is the usual treatment for a few small patches of impetigo on the skin. Another medication called mupirocin cream also used to be used for mild uncomplicated impetigo, but is now reserved for infections caused by the MRSA germ. If it is not too sore, the crusts should be cleaned off with warm soapy water before the cream is applied. This allows the antibiotic to penetrate into the skin.

Antibiotic treatment in the form of liquid medicine or tablets may be prescribed to treat impetigo in some situations. This may be needed if, for example:

  • The rash is more widespread.
  • The infection is spreading, despite using the cream.
  • The infection has come back despite treatment.
  • You have a poor immune system.
  • You are generally unwell with symptoms such as high temperature (fever) and swollen lymph glands.

In such cases, the treatment of choice is oral flucloxacillin for seven days. However, if you are allergic to penicillin, the recommended alternative is oral clarithromycin for the same length of time. Other antibiotic medicines may be used if the infection is MRSA.

Avoiding passing impetigo on to others

As impetigo is contagious (ie the infected person can pass it on by touching):

  • Try not to touch patches of impetigo and do not allow other children to touch them.
  • Wash your hands after touching a patch of impetigo and after applying antibiotic cream.
  • Don’t share towels, flannels, bathwater, etc, until the infection has gone.
  • Children should be kept off school or nursery until there is no more blistering or crusting, or until 48 hours after antibiotic treatment has been started.
  • Adults with impetigo should also stay off work until crusts have dried and scabbed over, or until 48 hours after antibiotics have been started.

Some uncommon aspects of impetigo

If treatment does not work

Tell your doctor if the initial treatment does not work. A possible cause for this is if the germ (bacterium) causing the infection is resistant to the prescribed cream or tablet. A switch to a different antibiotic is sometimes needed if the first does not work. Sometimes your doctor will take a swab to see which germ is causing the infection. A swab is a small ball of cotton wool on the end of a stick which is used to obtain mucus and cells. This sample is examined under a microscope in a laboratory. The result will help guide the best choice of treatment.

If your impetigo returns (recurs)

It is common for children to have one or two bouts of impetigo at some stage. However, some people have recurring bouts of impetigo. A possible cause for this is that the bacteria that cause the infection can sometimes live in (‘colonise’) the nose. They do no harm there but sometimes spread out and multiply on the face to cause impetigo. If this is suspected, your doctor may take a swab of the nose. The swab is then sent to the laboratory to look for certain colonising bacteria. If necessary, a course of antibiotic cream applied to the area just inside the nose can clear these bacteria. The cream most often used in these cases is called Naseptin®.

Some things to look out for

Another skin infection called cellulitis is sometimes mistaken for impetigo. Cellulitis is a ‘deeper’ skin infection. Normally, with cellulitis the area of skin affected is larger, the skin is red, swollen and tender and there are not usually any blisters or crusts. Cellulitis usually needs prompt treatment. See the separate leaflet called Cellulitis and Erysipelas for more details. In particular, see a doctor urgently if cellulitis develops close to an eye.

A patch of impetigo on the face near to the mouth is sometimes confused with a cold sore. Cold sores are due to a viral infection and tend to recur in the same place from time to time. See the separate leaflet called Cold Sores for more details.


I am 21-years-old and have recurrent impetigo. I usually get outbreaks on my chin or on my nose.

Each outbreak follows the symptoms of impetigo exactly and the rash responds immediately to antibiotics but I get it about once every two months or so.

I have had the blisters cultured twice in order to dispel any possibility of herpes and the cultures came back negative both times (two separate doctors performed these tests).

I now wash my face daily with an over-the-counter antibacterial face wash in an attempt to prevent outbreak, but I just got impetigo again today.

Have you ever heard of someone getting impetigo so often and at my age?

Why do you think I keep getting it? Do you have any suggestions as to how I can rid myself of this awful infection?


The bacteria staphylococcus aureus is the most frequent cause of superficial skin infections such as impetigo.

At least 10 per cent of healthy people carry the organism in the front of their nose and it is possible therefore for the nose to be the source of recurrent infection.

If this is so, a course of nasal treatment with an antibiotic ointment may get rid of the organism and reduce the risk of recurrent infection.

Visit your doctor to discuss the pattern of infection that you have experienced, as rarely, this may indicate an underlying systemic disorder such as diabetes or a problem affecting the immune system.

They will be able to perform blood tests to exclude such conditions and help you in combating future infection.

Yours sincerely

The NetDoctor Medical team

Last updated 19.03.2014

What Is It?

Published: April, 2019

Impetigo is a highly contagious bacterial skin infection, usually caused by Group A streptococcus or Staphylococcus aureus bacteria. Impetigo is most common in children. However, it sometimes occurs in adults who have other itchy skin conditions, such as eczema. Other conditions that increase your risk of developing impetigo include chickenpox, reactions to insect bites, burns of the skin and diabetes.

Impetigo often appears around the nose and mouth. However, it can develop wherever the skin is broken by cuts, scrapes, scratching, or cold sores, and where bacteria can enter.

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Skin Infections

The three most common skin infections in athletes are:

  • Staphylococcus aureus “Staph”
    Staphylococcus aureus is a bacteria. Sometimes it is resistant to certain types of antibiotics and is called MRSA. Staph typically causes one or more painful sores, with pus surrounded by redness, sometimes associated with fever.
    • A Good Offense is Still the Best Defense!
      Staph prevention poster for athletes.
    • MRSA: Information for Coaches and Athletes
      Fact sheet with frequently asked questions about CA-MRSA for athletes and coaches.
  • Herpes gladiatorum
    Herpes is the same virus that causes cold sores in the mouth. Typically it causes one or more painful blisters with clear fluid surrounded by redness.
  • NIH: Tinea “Ringworm”
    Ringworm is a fungus on the skin. Typically it causes itchy, dry, red, circular patches.

These infections can lead to:

  • Lost playing time
  • Wounds or rashes that keep coming back
  • Hair loss
  • Scarring, sometimes on face
  • Rarely, serious life-threatening infections if not treated quickly

Get it checked out. Don’t wait.

  • Report any skin problems to your athletic trainer, school nurse, coach, or health care provider.
  • Tell your health care provider you participate in competitive sports.
  • Check with league rules if you have questions about participation.

What are the risk factors for passing skin infections from one person to another?

  • Skin-to-skin contact
    • Wrestling and football are the sports with the most number of outbreaks.
    • Outbreaks have been reported among participants in many other sports .
  • Inadequate hand washing .
  • Sharing sweaty or dirty clothes, towels, or equipment.
  • Breaks in the skin, sores, or open wounds particularly if they are draining fluid and are not covered by a bandage that covers the entire wound.
  • Not showering after every practice or game.

What Are the Signs of Impetigo?

Impetigo starts out as a small cluster of blisters that after a few hours breaks into a red, moist area that oozes or weeps fluid. Impetigo appears mainly on the face but also can develop on exposed areas of the arms and legs.

In a few days, there is the formation of a golden or dark-yellow crust resembling grains of brown sugar. The infection may continue to spread at the edges of the infected area or affect other areas of skin.

Impetigo can be spread by skin-to-skin or infected surface-to-skin (such as towels) contact.

Call Your Doctor About Impetigo if:

  • You have sores or a rash that worsens or becomes more uncomfortable. An impetigo infection needs prompt medical attention.
  • Small, pus-filled sores form, with a dark brown crust. This indicates ecthyma, a deeper form of skin infection that penetrates into the skin. If left untreated, it may cause scarring and permanent changes in skin pigmentation.

NOTE: Sores associated with impetigo may be mistaken for herpes, a viral infection. Impetigo spreads faster and never develops inside the mouth. If in doubt, see a doctor for an accurate diagnosis.

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What Is Impetigo?

Impetigo (pronounced: im-peh-TY-go) is a very common skin infection, especially in young kids. But anyone can get it. It can cause blisters or sores on the face, hands, and legs.

Someone can be more likely to develop impetigo when their skin is already irritated by another problem, such as eczema, poison ivy, insect bites, and cuts or scrapes. Scratching a sore or a rash is a common cause — for example, poison ivy can get infected and turn into impetigo. It also happens more often in warm, humid environments.

Washing your hands and face well and often can help prevent it.

What Are the Signs & Symptoms of Impetigo?

Impetigo may affect skin anywhere on the body, but is most common around the nose and mouth, hands, and forearms.

The three types of impetigo are non-bullous (crusted), bullous (large blisters), and ecthyma (ulcers):

  • Non-bullous or crusted impetigo is most common. It begins as tiny blisters that eventually burst and leave small wet patches of red skin that may weep fluid. Gradually, a yellowish-brown or tan crust covers the area, making it look like it has been coated with honey or brown sugar.
  • Bullous impetigo causes larger fluid-containing blisters that look clear, then cloudy. These blisters are more likely to stay longer on the skin without bursting.
  • Ecthyma impetigo looks like “punched out” ulcers with yellow crust and red edges.

Is Impetigo Contagious?

Impetigo is contagious, and can spread from one person to another. It’s usually caused by one of two bacteria: Staphylococcus aureus or Streptococcus pyogenes (also called group A streptococcus, which also causes strep throat). Methicillin-resistant Staphylococcus aureus (MRSA) is also becoming an important cause of impetigo.

Impetigo can spread to anyone who touches infected skin or items that have been touched by infected skin (such as clothing, towels, and bed linens). It can be itchy, so people also can spread the infection when they scratch it and then touch other parts of their body.

How Is Impetigo Diagnosed?

In most cases, doctors can diagnose impetigo based on how the rash looks. Occasionally, they may need to take a sample of fluid from blisters for testing.

How Is Impetigo Treated?

Impetigo is typically treated with antibiotics, either as an ointment or a medicine taken by mouth:

  • When it just affects a small area of the skin (and especially if it’s the non-bullous form), impetigo is treated with antibiotic ointment for 5 days.
  • If the infection has spread to other areas of the body or the ointment isn’t working, the doctor may prescribe an antibiotic pill or liquid to be taken for 7–10 days.

After antibiotic treatment begins, healing should start within a few days. It’s important to make sure that you take the medicine as prescribed. Otherwise, a deeper and more serious skin infection could develop.

While the infection is healing, gently wash your skin with clean gauze and antiseptic soap every day. Soak any areas of crusted skin with warm soapy water to help remove the layers of crust (you don’t have to remove all of it).

To keep impetigo from spreading to other parts of the body, the doctor or nurse will probably recommend covering infected areas with gauze and tape or a loose plastic bandage. Keep your fingernails short and clean to prevent scratching that could lead to a worse infection.

Can Impetigo Be Prevented?

Keeping skin clean can help prevent impetigo. Wash your hands well and often and take baths or showers regularly. Pay special attention to skin injuries (cuts, scrapes, bug bites, etc.), areas of eczema, and rashes such as poison ivy. Keep these areas clean and covered.

To prevent impetigo from spreading among family members, everyone should use their own clothing, sheets, razors, soaps, and towels. When these items get dirty, wash them separately in very hot water. Using paper towels instead of cloth towels also can help keep the infection from spreading to others. Sharing makeup is never a good idea but even more risky if you have impetigo.

When Should I Call the Doctor?

Call the doctor if you have signs of impetigo, especially if you’ve been around a family member, friend, or classmate with the infection.

Keep an eye on the sores and call the doctor if the skin doesn’t begin to heal after 3 days of treatment or you develop a fever. If the area around the rash becomes red, warm, or tender to the touch, call your doctor right away.

Reviewed by: Joanne Murren-Boezem, MD Date reviewed: June 2018

Herpes or Impetigo: The CBCD Highlights the Difference

“Infected with the herpes virus (HSV-1 or HSV-2)? The CBCD recommends taking Novirin or Gene-Eden-VIR.” – Greg Bennett, CBCD

“Herpes simplex virus (HSV) infection is the condition most often confused with impetigo.” (1) To prevent confusion, the Center for the Biology of Chronic Disease (CBCD) would like to highlight the difference between an infection with the herpes simplex virus (HSV-1 or HSV-2), and Impetigo, a bacterial skin infection.

How does one know the difference?

Clues to look for include intact vesicles (small, fluid-filled sacs that can appear on the skin). If they are intact (unbroken or weepy) then the infection is more likely to be HSV. Additionally, as time goes on, if the vesicles become cloudy and ultimately result in crusts that are honey colored, the infection is more likely to be herpes. Finally, a herpes infection is usually recurring. In other words, if an individual is infected, he or she is likely to have more than one outbreak of sores that turn into vesicles. This is not the case with Impetigo. “When an impetiginous pustule is unroofed, it is noticeably filled with pus. A herpetic lesion may appear to be pus filled, but when it is unroofed, only a scant amount of clear fluid is found.” (1) Finally, antibiotics are usually prescribed for an Impetigo infection, whereas antiviral drugs are usually prescribed for a herpes infection.

Click to learn more about herpes symptoms.

The Center for the Biology of Chronic Disease (CBCD) recommends that people infected with the herpes virus (HSV-1 or HSV-2) take Novirin or Gene-Eden-VIR. The formula of these natural antiviral products was tested by Hanan Polansky and Edan Itzkovitz from the CBCD in two clinical studies that followed FDA guidelines. The studies showed that the Gene-Eden-VIR and Novirin formula is effective against the herpes simplex virus, and other viruses. The clinical studies were published in the peer reviewed, medical journal Pharmacology & Pharmacy, the first, in a special edition on Advances in Antiviral Drugs. Study authors wrote that, “individuals infected with the HSV … reported a safe decrease in their symptoms following treatment with Gene-Eden-VIR.” (2) The study authors also wrote that, “we observed a statistically significant decrease in the severity, duration, and frequency of symptoms.” (2)

Both products can be ordered online on the Novirin and Gene-Eden-VIR websites.

Novirin and Gene-Eden-VIR are natural antiviral dietary supplements. Their formula contains five natural ingredients: Selenium, Camellia Sinesis Extract, Quercetin, Cinnamomum Extract, and Licorice Extract. The first ingredient is a trace element, and the other four are plant extracts. Each ingredient and its dose was chosen through a scientific approach. Scientists at polyDNA, the company that invented and patented the formula, scanned thousands of scientific and medical papers published in various medical and scientific journals, and identified the safest and most effective natural ingredients against latent viruses. To date, Novirin and Gene-Eden-VIR are the only natural antiviral products on the market with published clinical studies that support their claims.

“Impetigo is a skin infection seen in all age groups, but it is most common among children. Impetigo is caused by common bacteria, and it often starts as a minor scratch. It is more prevalent during warm weather, particularly among children who live in crowded conditions. The disease can be severe and dangerous in newborn infants. Impetigo first appears as a sore, often on the upper lip. It may resemble a cold sore or fever blister caused by herpes simplex virus – a virus that can spread by direct contact and may cause serious problems in children. A physician should be contacted to diagnose the condition correctly and treat it accordingly. A blister may form and, after it breaks, the secretion dries to form a thick, soft, golden crust. When the crust is removed clear, honey-colored fluid oozes from the raw sore. The sores may spread to other parts of the face, hands, or the body.” (3) Generally, treatment consists of systemic antibiotics (usually penicillin, or erythromycin for patients who are allergic to penicillin), which also help prevent glomerulonephritis (inflammation of the kidney that can have serious complications).

What treatments are available for a herpes infection?

“Two types of antiviral treatments against HSV are available: topical and oral. The treatments include penciclovir, acyclovir, famciclovir, and valaciclovir. However, their effectiveness is limited. For instance, a meta-analysis of five placebo-controlled and two dose comparison studies evaluated the effect of aciclovir, famciclovir or valaciclovir on symptoms. The meta-analysis showed that oral antiviral therapy decreases the duration and the associated pain of an outbreak by merely one day.” (2) There are also natural remedies that target the latent HSV. Two of these clinically backed remedies are Novirin and Gene-Eden-VIR.

The CBCD recommends that individuals infected with the herpes virus (HSV-1 or HSV-2) take Novirin or Gene-Eden-VIR.

Click to read more about Novirin and the herpes virus, or Gene-Eden-VIR and the herpes virus.

(1) Pediatric Care Online – Bacterial Skin Infections – Impetigo. Last updated June 24, 2014.

(3) – Impetigo.

About CBCD

About CBCD

The Center for the Biology of Chronic Disease ( is a not-for-profit tax-exempt organization under section 501(c) 3 of the IRS tax code. The center’s mission is to advance the research on the biology of chronic disease and to accelerate the discovery of a cure for these diseases. The CBCD first published Dr. Hanan Polansky’s highly acclaimed “Purple” book, entitled “Microcompetition with Foreign DNA and the Origin of Chronic Disease” in 2003. In this book, he explains how foreign DNA fragments can cause many major diseases. The book has been read by more than 5,000 scientists around the world, and has been reviewed in more than 20 leading scientific journals. These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.


It’s a scary sight when your child comes home from day care or elementary school with red sores and oozing fluid-filled blisters. Don’t be alarmed if it’s impetigo. Impetigo — one of the most common childhood diseases — can be treated with medications approved by the U.S. Food and Drug Administration (FDA).

Impetigo is a common bacterial skin infection that can produce blisters or sores anywhere on the body, but usually on the face (around the nose and mouth), neck, hands, and diaper area. It’s contagious, preventable, and manageable with antibiotics, says pediatrician Thomas D. Smith, MD, of FDA.

What Causes Impetigo

Two types of bacteria found on our skin cause impetigo: Staphylococcus aureus and Streptococcus pyogenes (which also causes strep throat). Most of us go about our lives carrying around these bacteria without a problem, Smith says. But then a minor cut, scrape or insect bite allows the bacteria to cause an infection, resulting in impetigo.

Anyone can get impetigo — and more than once, Smith says. Although impetigo is a year-round disease, it occurs most often during the warm weather months. There are more than 3 million cases of impetigo in the United States every year.

“We typically see impetigo with kids 2 to 6 years old, probably because they get more cuts and scrapes and scratch more. And that spreads the bacteria,” Smith says.

Treating Impetigo

Look for these signs of impetigo:

  • itchy red sores that fill with fluid and then burst open, forming a yellow crust
  • itchy rash
  • fluid-filled blisters

If you see those symptoms, visit your health care provider. Impetigo is usually treated with topical or oral antibiotics. If you have multiple lesions or if there is an outbreak, your doctor might prescribe an oral antibiotic. There is no over-the-counter (OTC) treatment for impetigo.

Controlling and Preventing Impetigo

Untreated, impetigo often clears up on its own after a few days or weeks, Smith says. The key is to keep the infected area clean with soap and water and not to scratch it. The downside of not treating impetigo is that some people might develop more lesions that spread to other areas of their body.

And you can infect others. “To spread impetigo, you need fairly close contact — not casual contact — with the infected person or the objects they touched,” he says. Avoid spreading impetigo to other people or other parts of your body by:

  • Cleaning the infected areas with soap and water.
  • Loosely covering scabs and sores until they heal.
  • Gently removing crusty scabs.
  • Washing your hands with soap and water after touching infected areas or infected persons.

Because impetigo spreads by skin-to-skin contact, there often are small outbreaks within a family or a classroom, Smith says. Avoid touching objects that someone with impetigo has used, such as utensils, towels, sheets, clothing and toys. If you have impetigo, keep your fingernails short so the bacteria can’t live under your nails and spread. Also, don’t scratch the sores.

Call your health care provider if the symptoms don’t go away or if there are signs the infection has worsened, such as fever, pain, or increased swelling.

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