What Causes Impetigo? The Risk Factors to Know and How to Prevent The Condition

Some people with impetigo also develop deeper ulcerations and blisters that can be painful. This is known as ecthyma, and it can occur when impetigo is left untreated. (1)

Impetigo isn’t immediately dangerous or life-threatening if treated, but it can spread quickly among peers. It can become a problem in schools and on sports teams.

As with other types of contagious skin conditions, it is possible to prevent impetigo and stop its spread. Prevention starts with understanding what causes this skin infection, and understanding who’s at risk.

What Are the Most Common Causes of Impetigo?

Impetigo is a superficial infection usually caused by one of two bacteria: Staphyloccocus aureus or Streptococcus pyogenes. The strep bacteria is the same one that causes strep throat, whereas the staph bacteria can be MRSA, a particular strain resistant to many antibiotics. (2)

What to Know About the Different Types of Streptococci

If you have a skin injury like a cut or a scrape, or if you’re bitten by an animal or insect, either bacteria can invade your skin and cause an infection on the top layer of your skin.

But this isn’t the only way to get impetigo. Because this condition is contagious, you can also become infected if you come in contact with the sores of someone who’ve been infected, or if you share or touch items that they’ve touched. (3)

These items may include: (1)

  • Bed sheets and covers
  • Towels
  • Loofah sponges
  • Clothing
  • Countertops and other surfaces
  • Door knobs

What Are the Main Risk Factors for Impetigo That You Should Know?

Even though touching contaminated items and surfaces can spread impetigo, certain factors also increase your risk for this bacterial infection:


Impetigo can occur in people of all ages, including teenagers and adults. But it most commonly occurs in young children 2 to 5, says Charles I. Shubin, MD, a pediatric doctor with Mercy Family Care Physicians in Baltimore. (1)

Close Proximity to Another Infection

Because skin-to-skin contact increases the likelihood of spreading impetigo to others, this condition can become widespread in places where people are in close contact with others. This includes schools and day-care settings. Impetigo can also spread from person to person on the job and at home. (1)

Warm, Humid Weather

The bacteria that causes impetigo thrives in humidity and warmth. The risk of developing this skin condition increases during the summer, and there are more cases of impetigo in areas with hot and humid climate. In the United States, people tend to develop this condition during the summer or fall. (3)

Participation in Sports

Being an athlete in and of itself doesn’t cause impetigo. But if you participate in sports that involve skin-to-skin contact with other players, there’s a greater risk of developing this skin infection. Keep in mind that you’ll only get impetigo if you have a skin injury or come in contact with a person who has the condition. Sports that put you at risk include football or wrestling. (3)

Broken Skin

Broken skin also provides an entry point for the staph or strep bacteria. One of the best ways to protect yourself is to practice good wound care. This includes washing wounds, applying topical antibiotic ointment, and keeping wounds covered with gauze until they heal. (1)

How to Help Prevent the Spread of Impetigo

Impetigo prevention not only aims to stop the infection from infecting other people, but also to stop the infection from spreading to other parts of your body.

Impetigo is a skin infection that can clear up on its own. (4) “Even without medication, most impetigo should be expected to resolve within two to three weeks,” says Rick Pescatore, DO, director of research at Crozer-Keystone Health System Emergency Medicine in Philadelphia.

“Using medication like topical mupirocin can speed that timeline by about a week, and prevent secondary or recurrent infections, which can complicate the initial episode of impetigo,” he says.

Treatment is recommended to avoid infecting others. Antibiotics are commonly used for impetigo. These include topical antibiotics, oral antibiotics, and even antibiotic injections.

It takes time for antibiotics to get into your system. So, you’ll remain contagious for about 24 to 48 hours after beginning a course of medication. (4)

Here are a few tips to prevent spreading impetigo to others, and to other parts of your body:

Don’t share personal items. If a person with impetigo touches their sores and then touches an item, this item becomes contaminated. Therefore, it’s important to avoid contact with any contaminated surfaces. Don't share razors, towels, wash cloths, or other personal items. Keep in mind that impetigo can also pass from person-to-person via toys. If you notice anyone with sores or blisters that look like impetigo, avoid physical contact with the person or items they’ve touched. (2)

Disinfect surfaces. Disinfecting commonly touched surfaces is another way to help prevent the spread of impetigo. If you work in a school or day-care setting, use disinfecting wipes on countertops, door handles, and light switches to reduce the risk of infecting people. Take similar measures at home and keep commonly touched surfaces germ free. (5)

5 Simple Habits for Healthier Skin

Don’t touch your sores or blisters. The less you touch your own sores and blisters, the less likely that you’ll spread impetigo to other parts of your body. Make sure you wash your hands after caring for your lesions. Use a disposable paper towel when drying hands, and don’t reuse cloths. (5)

Change your towel and washcloth daily. You can also stop the spread of the infection by using a clean towel and wash cloth every time you bathe. Wash your sheets, linens, and bath towels in hot water. (1,5)

Apply anti-itch cream. Impetigo can be itchy, and it’s important that you don’t scratch the lesions, since the bacteria can get underneath your nails and spread to other parts of your body. Apply anti-itch medicine to lesions, and trim your nails to avoid damaging your skin, which can make impetigo worse. (5)

Keep your sores clean and covered. Even accidental contact with someone who has impetigo can spread the infection. If your child has lesions, make sure you keep the sores or blisters covered with gauze and tape until the skin heals, warns Dr. Shubin. Keeping sores covered can also protect other family members, especially when they share a bed with an infected person.

Unfortunately, even after impetigo heals, it’s possible for an infection to return. Applying the above tips will also help prevent repeated infections: not sharing personal items, properly caring for wounds, and avoiding skin-to- skin contact. You can also protect yourself by showering after every workout to remove bacteria from your skin. (5)

While treating impetigo, make sure you only wear clean clothes and wash any worn clothes in hot water. (5) In addition, Shubin encourages washing your hands frequently with soap and warm water, especially after shaking hands with someone.

Be sure to practice proper hand washing techniques. Don’t just run water over your hands. You’ll need to rub your hands together vigorously for at least 20 seconds. The right way to wash your hands include: (6)

  • Wet your hands with warm running water.
  • Apply soap and rub your hands together to create a lather.
  • Rub your hands together for at least 20 seconds. (Sing or hum the "Happy Birthday" song from beginning to end twice.)
  • Scrub the front and back of your hands, and in between your fingers.
  • Rinse your hands with clean water.
  • Dry your hands using a clean cloth.

Sometimes, you may not have access to water or soap. If not, protect yourself by using an alcohol-based hand sanitizer. Make sure the product contains at least 60 percent alcohol. (7)

Soap and water are best, but sanitizers can reduce a number of germs on your hands and help reduce the risk of bacterial infections.

To apply gel properly, pour a small amount into the palm of your hand, rub your hands together, and then allow your hands to air dry. From start to finish, applying hand sanitizer should take about 20 seconds. (7)

A Final Word on Impetigo: Skin Infections Are Preventable

Impetigo often looks worse than it actually is, but even though this isn’t a particularly dangerous skin condition, there’s the risk of complications when left untreated.

It can lead to permanent skin scarring and kidney inflammation. Impetigo can also lead to cellulitis, an infection that affects the tissue underneath the skin. This infection can also spread to the lymph nodes and bloodstream and become life-threatening.

Learn how to recognize the signs and symptoms of impetigo, and then seek medical treatment if you suspect an infection. Early treatment is one of the best ways to prevent complications and stop the spread of the infection. (1)

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