Impetigo is a common and contagious skin infection. Bacteria like Staphylococcus aureus or Streptococcus pyogenes infect the outer layers of skin, called the epidermis. The face, arms, and legs are most often affected.

Anyone can get impetigo, but it most commonly affects children, especially those ages 2 to 5.

The infection often begins in minor cuts, insect bites, or a rash such as eczema — any place where the skin is broken. But it can also occur on healthy skin.

It’s called primary impetigo when it infects healthy skin and secondary impetigo when it occurs in broken skin. It isn’t always easy or necessary to make this distinction.

Impetigo is an old disease. The name dates back to 14th-century England and comes from the Latin word impetere, meaning “to attack.” “Attack” seems a fitting description for this easily spread infection.

Bacteria thrive in hot, moist conditions. So impetigo tends to be seasonal, peaking in the summer and fall in northern climates. In warm and humid climates, it tends to occur year-round.

An estimated 162 million children worldwide have impetigo at any one time. Impetigo is more common in developing countries and in poor areas of industrial countries. The highest numbers of cases are in areas like Oceania, which includes Australia, New Zealand, and several other countries.

Impetigo is an infection caused by strains of staph or strep bacteria. These bacteria can get into your body through a break in the skin from a cut, scratch, insect bite, or rash. Then they can invade and colonize.

The condition can be contagious. You can catch these bacteria if you touch the sores of a person with impetigo or you touch items like towels, clothes, or sheets that the person used.

However, these bacteria are also common in our environment, and most people who come in contact with them won’t necessarily develop impetigo.

Some people normally carry staph bacteria on the inside of their nose. They may get infected if the bacteria spreads to their skin.

Adults and children are at higher risk for impetigo if they:

The first signs of impetigo are reddish sores on the skin, often clustered around the nose and lips. These sores quickly grow into blisters, ooze and burst, and then form a yellowish crust. The clusters of blisters may expand to cover more of the skin. Sometimes the red spots just develop a yellowish crust without any blisters being seen.

The sores can be itchy and occasionally painful. After the crust phase, they form red marks that fade without leaving scars.

Infants sometimes have a less common type of impetigo, with larger blisters around the diaper area or in skin folds. These fluid-filled blisters soon burst, leaving a scaly rim called a collarette.

Impetigo can be uncomfortable. Occasionally, it may involve swollen glands in the area of the outbreak or a fever.

It’s a good idea to see your doctor if you suspect impetigo. Your doctor can usually diagnose the infection by its appearance.

If the sores don’t clear up with treatment, the doctor may want to culture the bacteria. This involves taking a little bit of the liquid that comes out of the sore and testing it to see what type of bacteria caused it to determine which antibiotics will work best against it.

Antibiotics are effective against impetigo. Which type of antibiotic you get depends on how widespread or severe the blisters are.

If you have impetigo in only a small area of your skin, topical antibiotics are the preferred treatment. Options include mupirocin cream or ointment (Bactroban or Centany) and retapamulin ointment (Altabax).

If your impetigo is severe or widespread, your doctor can prescribe oral antibiotics such as amoxicillin/clavulanate (Augmentin), certain cephalosporins, or clindamycin (Cleocin). These drugs may work more quickly than topical antibiotics, but they aren’t necessarily better at clearing the infection.

Oral antibiotics can also cause more side effects than topical antibiotics, such as nausea.

With treatment, impetigo usually heals in 7 to 10 days. If you have an underlying infection or skin disease, the infection may take longer to heal.

Although impetigo is more common in young children, adults can get it too. Because it’s so contagious, impetigo can spread through any close contact. Adults who play sports often catch it from skin-to-skin contact.

The symptoms of impetigo in adults are sores around the nose and mouth or other exposed areas of the body that break open, ooze, and then crust.

Generally, impetigo is a mild skin condition, but adults have a higher risk of complications than children. These include:

Impetigo isn’t the only infectious rash adults get. Here are a few other contagious skin conditions.

Toddlers are the most likely age group to develop impetigo. The infection looks different on young children than it does on adults. Parents may see sores around their child’s nose and mouth, as well as on the trunk, hands, feet, and in the diaper area.

In young children, often the cause is scratching at an insect bite or scrape on the skin. Scratching allows bacteria to get into the skin.

Continuing to scratch can cause a more serious infection or lead to scarring.

Parents can help prevent complications by covering the sores and cutting their child’s nails.

There are three types of impetigo based on the bacteria that cause them and the sores they form. Each type goes through a series of stages.

Nonbullous

Nonbullous impetigo is mainly caused by Staphylococcus aureus. It’s the most common form of impetigo, causing an estimated 70 percent of cases.

It goes through the following stages:

  • It usually starts with reddish, itchy sores around the mouth and nose.
  • The sores break open, leaving red and irritated skin around them.
  • A brownish-yellow crust forms.
  • When the crusts heal, there are reddish spots that fade and don’t leave scars.

Bullous

Bullous impetigo is almost always caused by Staphylococcus aureus bacteria.

  • It usually forms larger blisters or bullae filled with a clear fluid that may become darker and cloudy. The blisters start on unbroken skin and aren’t surrounded by reddish areas.
  • The blisters become limp and clear, and then burst open.
  • A yellowish, crusty sore forms over the area where the blisters broke open.
  • The blisters usually leave no scars behind when they heal.

Ecthyma

This more serious infection is much less common. It occasionally happens when impetigo isn’t treated.Ecthyma goes deeper into the skin than the other forms of impetigo, and it’s more severe.

  • The infection forms painful blisters on the skin of the buttocks, thighs, legs, ankles, and feet.
  • The blisters turn into pus-filled sores with a thicker crust.
  • Often, the skin around the sores turns red.
  • Ecthyma sores heal slowly and may leave scars after they heal.

Antibiotics are the main treatment for impetigo, but you may be able to help the infection heal faster with home treatments in addition to treatment recommended by your doctor.

Clean and soak the sores three to four times a day until the sores heal. Gently clean the sores with warm water and soap, and then remove the crusts. Wash your hands thoroughly after treating the sores to avoid spreading the infection.

Dry the area and apply the prescription antibiotic ointment as directed. Then cover the sores lightly with gauze if they are in an area where you can do this.

For a minor outbreak, you can use an over-the-counter (OTC) antibiotic ointment, Apply it three times a day after cleaning the area. Then cover the sore with a bandage or gauze. After a few days, if you don’t see improvement, you should see your doctor.

Another home treatment is a 15-minute bath with a very dilute solution of household bleach (2.2 percent). This reduces the number of bacteria on the skin, if you use it regularly.

For a full-size bath, use 1/2 cup of bleach. Rinse off with warm water and pat dry afterward.

Use caution if you have sensitive skin. Some people have an allergic reaction to bleach.

A number of home remedies are also available at your drugstore or natural products store. Using them correctly might improve the odds that they’ll help your impetigo, though they haven’t been shown to effectively treat impetigo on their own.

Children with impetigo should stay home until they are no longer contagious if the lesions can’t be reliably covered. Adults who work in jobs that involve close contact should ask their doctor when it’s safe for them to return to work.

Good hygiene is the no. 1 way to prevent impetigo. Follow these tips:

  • Bathe and wash your hands often to cut down on skin bacteria.
  • Cover any skin wounds or insect bites to protect the area.
  • Keep your nails clipped and clean.
  • Don’t touch or scratch open sores. This will spread the infection.
  • Wash everything that comes into contact with the impetigo sores in hot water and laundry bleach.
  • Change bed linens, towels, and clothing that come in contact with the sores often, until the sores are no longer contagious.
  • Clean and disinfect surfaces, equipment, and toys that may have come in contact with impetigo.
  • Don’t share any personal items with someone who has impetigo.

The open sores are highly contagious. Scratching the sores can spread the infection from one place on your skin to another, or to another person. The infection can also spread from anything an infected person touches.

Because it spreads so easily, impetigo is sometimes called the school disease. It can quickly spread from child to child in a classroom or day care center where children are in close contact. For the same reason, it also spreads easily in families.

Hygiene is key to controlling impetigo’s spread. If you or your child has impetigo, wash and disinfect everything the infection might come into contact with, including clothes, bedding, towels, toys, or sports equipment.

Topical antibiotics such as mupirocin can usually clear up impetigo in a few days and shorten the length of time that the disease is contagious. Oral antibiotics stop the infection from being contagious after 24 to 48 hours.

Like impetigo, cold sores are blisters that form around your mouth. You might also see them on your nose or fingers.

Cold sores are caused by the herpes simplex virus (HSV). This virus comes in two forms: HSV-1 and HSV-2. Usually, HSV-1 causes cold sores, while HSV-2 causes genital herpes.

Antiviral creams and pills treat cold sores if necessary. You can spread or catch the virus that causes cold sores though kissing. The sores remain infectious until they crust over, so avoid kissing anyone who has never had cold sores until that time.

Cold sores form in five stages. Learn what to expect after you see one pop up.

Essential oils are liquids extracted from plants. Dozens of essential oils have antibacterial properties. This suggests that essential oils may be useful for treating impetigo, though currently there is no research to support this.

These products could have advantages over antibiotics, because some of the bacteria that cause impetigo have become resistant to current antibiotic drugs.

Geranium, patchouli, and tea tree oil are a few of the essential oils that may be helpful for treating impetigo.

Before you try any essential oil or other alternative treatment, talk to your doctor. Some of these products can cause side effects, and they may not be safe for everyone.

More than 90 different types of essential oils exist. Each has its own unique health benefits.

Ringworm is a fungal infection of the skin. The name refers to the ring-like shape of the red, raised skin patches it produces. Unlike impetigo, ringworm doesn’t cause yellow crusting.

You can catch ringworm through direct contact or by sharing personal items with people who are infected. The ring may appear on the scalp, body, skin around the groin (called jock itch), or feet (called athlete’s foot).

The typical treatment is with an antifungal skin cream. Some products are available over the counter. Others require a prescription from your doctor.

Ringworm is an itchy, annoying problem. Good hygiene can help prevent it from starting or coming back.

Erysipelas is a bacterial infection that affects the upper layers of skin. It’s caused by the same strep bacteria that are responsible for strep throat. Similar to impetigo, these bacteria sneak into the skin through an open wound or crack.

Erysipelas causes blisters on the face and legs. Other symptoms include a fever and chills.

Doctors typically prescribe oral antibiotics to treat the infection. More severe cases may need to be treated with IV antibiotics in a hospital.

Treatment is usually very effective at eliminating the infection. Not treating erysipelas can increase your risk for serious complications.

Eczema isn’t an infection. Instead, it can be a reaction to substances in your environment, like detergent, metal, or latex, or it may be associated with allergies or asthma.

Symptoms of eczema include:

  • red, itchy skin
  • dry skin

One type called dyshidrotic eczema causes tiny fluid-filled blisters to form on your hands or feet. These blisters may itch or hurt.

People who have allergies are more likely to get eczema. Avoiding the substance that caused the skin reaction can prevent it in the future.

Eczema comes in seven different types. Learn how to identify them.

Impetigo is a highly contagious bacterial skin infection that generally isn’t serious. It clears up faster with antibiotics and requires good hygiene to prevent it from spreading.

If you suspect that you or a loved one has impetigo, contact your doctor for diagnosis.