Impetigo: Causes, Symptoms,Types & Prevention


What is impetigo?

Impetigo, one of the most common skin infections among kids, usually produces blisters or sores on the face, neck, hands, and diaper area.

This contagious superficial skin infection is generally 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 usually affects preschool and school-age children. A child may be more likely to develop impetigo if the skin has already been irritated by other skin problems, such as eczema, poison ivy, insect bites, and cuts or scrapes.

Routinely washing the face and hands can help prevent impetigo, which often develops when there is a sore or a rash that has been scratched repeatedly (for example, poison ivy can get infected and turn into impetigo).

Doctors can usually diagnose impetigo based on the appearance of the rash. Occasionally, they may need to take a sample of fluid from blisters. Impetigo is typically treated with either an antibiotic ointment or medication taken by mouth.

Types of impetigo

There are several different types of impetigo. The symptoms and causes are what set each type apart from the others.

Impetigo contagiosa


This may also be called nonbullous impetigo, and is the most common type of impetigo in children. It is very contagious. This type of impetigo usually begins with red sores around the nose and mouth.

These blisters burst, leaving a weeping, red rash that becomes crusted. This rash may be itchy but is not painful. Swollen lymph nodes (bean shaped glands that help your body fight infection) may also occur with impetigo contagiosa.

Bullous impetigo


This form of impetigo is most common in children under age two. Blisters usually appear first on the torso, arms, and legs. These blisters may initially appear clear and then turn cloudy.

Blisters caused by bullous impetigo tend to last longer than blisters caused by other types of impetigo. The areas around the blisters may be red and itchy.



This is the most serious form of impetigo because it affects the second layer of the skin, rather than just the top layer. Blisters tend to be painful and may turn into ulcers, or aggravated, open sores. Swollen lymph nodes and scars may also occur.

Symptoms of impetigo

You or your child may have impetigo if you have sores:

  • That begin as small red spots, then change to blisters that eventually break open. The sores are typically not painful, but they may be itchy.
  • That ooze fluid and look crusty.
  • That increase in size and number. Sores may be as small as a pimple or larger than a coin.

Causes of impetigo

Impetigo occurs when the skin becomes infected with bacteria, usually either Staphylococcus aureus or Streptococcus pyogenes.

The bacteria can infect the skin in two main ways:

  • through a break in otherwise healthy skin  such as a cut, insect bite or other injury – this is known as primary impetigo
  • through skin damaged by another underlying skin condition, such as head lice, scabies or eczema – this is known as secondary impetigo

The bacteria can be spread easily through close contact with someone who has the infection, such as through direct physical contact, or by sharing towels or flannels.

As the condition doesn’t cause any symptoms until four to 10 days after initial exposure to the bacteria, it’s often easily spread to others unintentionally.

Children and people with diabetes or a weakened immune system– either due to a condition such as HIV or a treatment such as chemotherapy – are most at risk of developing impetigo.

Who gets impetigo?

Certain individuals are more likely than others to develop impetigo. Risk factors include:

  • being two to six years of age
  • regularly attending a daycare or school
  • having skin irritated by other conditions
  • poor hygiene
  • warm weather
  • being in a crowded environment where bacteria can spread easily
  • having dermatitis (itchy, inflammation of the skin, sometimes caused by allergic reactions)
  • participating in activities that involve skin-to-skin contact
  • having diabetes
  • having a compromised immune system

Diagnosis of impetigo

Your doctor can usually diagnose impetigo just by looking at your or your child’s skin. Sometimes your doctor will gently remove a small piece of a sore to send to a lab to identify the bacteria. If you or your child has other signs of illness, your doctor may order blood or urine tests.

Impetigo treatment

Treatment for impetigo depends on the severity of the symptoms as well as the type of bacteria causing the impetigo. If you have a mild case of impetigo, your doctor may recommend simple hygiene methods to help the skin heal and to prevent impetigo from spreading.

At-Home treatments

The affected area should be cleaned several times per day, using either water or an antibacterial wash. It is important not to scrub the area while washing it, as this can further irritate the skin. After washing, pat the skin dry and apply an antibacterial or over-the-counter antibiotic ointment according to your doctor’s recommendation.

If there are many scabs on the skin, you can soak this area to help remove some of the scabbing and promote healing. Affected areas can be soaked in soapy water or a 1:32 solution of vinegar and water (one ounce of vinegar for every 32 ounces of water.

Try to avoid picking at or touching the areas affected by impetigo. A non-stick dressing can be applied to reduce the spread of impetigo. Always wash your hands thoroughly after touching areas of your skin affected by impetigo.


If at-home treatment does not work or your impetigo is severe, your doctor may prescribe medication. Your doctor may prescribe a topical antibiotic cream to apply directly to your skin. It is important to clean the skin before applying the antibiotic cream, so it can penetrate the sores.

Your doctor may also prescribe oral antibiotics. These come in liquid form for children and pill form for adults. Whether you are prescribed topical or oral antibiotics, it is important to finish your prescription to prevent the infection from returning. Stopping an antibiotic regimen just because symptoms have improved can lead to a recurrence of the infection and antibiotic resistance.

Prevention of impetigo

Keeping skin clean can help prevent impetigo. Kids should wash their 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.

Anyone in your family with impetigo should keep fingernails cut short and the impetigo sores covered with gauze and tape.

Prevent impetigo infection from spreading among family members by making sure everyone uses their own clothing, sheets, razors, soaps, and towels. If necessary, substitute paper towels for cloth ones until the impetigo is gone. Separate the infected person’s bed linens, towels, and clothing from those of other family members, and wash these items in hot water. Keep the surfaces of your kitchen and household clean.

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