Impetigo is a common and highly contagious skin infection that involves blistering. It can happen when bacteria enter the skin through a cut or insect bite.
Impetigo is most common children aged 2–5 years, but it can happen at any age. It is more likely to occur during summer and fall and in humid or tropical climates.
Impetigo is rarely serious and usually disappears without treatment within 2 weeks. However, complications sometimes occur, and so a doctor may prescribe an antibiotic ointment or oral antibiotics.
The following images show some of the ways impetigo may appear on the skin.
Symptoms of impetigo usually appear 2–10 days after infection.
The main symptoms are blisters or sores that burst and ooze before drying up. Other symptoms will depend on the type of impetigo.
There are three types:
Around 80% of cases are of this type. It usually starts as a small blister but can spread quickly. The blisters often join together as it spreads.
The blisters tend to affect the face and the extremities.
As the blisters burst and weep, a honey-colored crust forms. There may also be redness and swelling in the area.
In rare cases, a person may have a fever and other systemic symptoms.
Nine out of 10 cases are among children under age 2.
This involves fewer blisters, but they are larger. They often affect the trunk of the body and may appear in the mouth.
The blisters contain a clear or yellow fluid, which becomes cloudy or dark over time. The blisters stay longer without bursting than in non-bullous impetigo. There is not usually redness or swelling, and there is no honey-colored crust.
However, as a blister bursts, it will leave a red mark with a scaly rim around it.
A fever and other general symptoms may occur.
In this type of impetigo, ulcers develop on the skin and enter the deeper layers.
The ulcers are indented into the skin with red or purple edges and a brown or honey-colored crust. They may produce pus.
Impetigo accounts for 10% of skin complaints in children.
To reduce the risk of a child passing on or catching impetigo, a child with impetigo should stay home until the lesions heal or until at least 24–48 hours after starting antibiotics. A doctor can advise when it will be safe to return to school or other public places.
To reduce the risk of impetigo spreading, parents and caregivers should ensure that children:
- wash their hands regularly
- avoid scratching or touching any wound or skin lesion
- avoid sharing personal items, such as washcloths or clothing
- clean any wounds with soap and water
- cover any open wounds
If a child has signs of impetigo, parents or caregiver should consult a doctor. If the child has a fever, seek urgent medical help.
In newborns, meningitis can sometimes develop.
A doctor can usually diagnose impetigo by looking at the symptoms.
- examine the affected area
- ask about any recent cuts, scrapes, or insect bites
- see if another skin condition is present, such as scabies
If symptoms are severe, persistent, or recurring, the doctor may do a swab test to identify which bacteria are present. This can help find the right antibiotic to treat the issue. It can also help rule out other possible causes, such as a fungal infection.
Treatment aims to:
- speed up healing
- improve the skin’s appearance
- stop the spread of the infection
- prevent complications
Treatment is usually with antibiotics. The type of antibiotic will depend on which bacteria are present and how severe the symptoms are.
Without treatment, the infection usually disappears in 2–3 weeks. With treatment, symptoms should disappear within 10 days.
In most cases, there will not be any scars, although the skin may be discolored.
Topical antibiotics are applied directly onto the skin. They include ointments such as mupirocin (Bactroban) and retapamulin (Altabax).
Before applying the ointment, wash the affected areas of skin with warm, soapy water. This allows the ingredients to penetrate more effectively.
If possible, use gloves when applying the cream. Wash the hands thoroughly after applying the ointment.
A doctor may prescribe oral antibiotics if symptoms are severe or have not responded to topical treatment.
The type of antibiotic will depend on:
- how severe the symptoms are
- the type of bacteria present
- the individual’s overall health
- whether they have any allergies
A course of antibiotics usually lasts at least 7 days. It is essential to complete the course even if symptoms clear up early. Otherwise, symptoms may return.
Some strains of S. aureus are resistant to antibiotics. This can make an infection difficult to treat.
While you may hear about alternative remedies for impetigo, there is not enough evidence to show these work.
- olive oil
- coconut oil
- Manuka honey
- tea tree oil
A person should follow a doctor’s instructions regarding treatment to prevent the spread of the infection.
People should never apply tea tree or other essential oils to the skin at full concentration. Always dilute them first. Tea tree oil can also trigger an allergic reaction in some people.
Impetigo happens when bacteria infect the skin either directly or through a break in the skin. They may enter through a wound, an insect bite, or lesions caused by another condition, such as eczema or scabies.
The bacteria that cause the infection are either Staphylococcus aureus (S. aureus) or Streptococcus pyogenes (S. pyogenes).
S. aureus exists harmlessly on human skin, and S. pyogenes is present in the normal mouth flora. However, they can cause infection when there is a cut or wound.
Impetigo is most likely to affect people who:
- spend time closely together, such as in a daycare center
- live in a warm, humid climate
- do activities that increase the risk of cuts and scrapes
- have scabies, eczema, or other skin conditions
People with a weakened immune system may have a higher risk of catching impetigo or developing severe symptoms or complications.
Impetigo is highly contagious once the sores and blister appear but not contagious before this stage. Once a person has been taking antibiotics for 24–48 hours, their case is no longer contagious.
A person can catch impetigo from another person by:
- touching an item that the person with an infection has used, such as a facecloth
- having physical contact with a person who has impetigo
Anyone with symptoms should stay home and follow the doctor’s advice on treatment.
Complications are rare. Around 1–5% of people with non-bullous impetigo develop post-streptococcal glomerulonephritis, a potentially life-threatening kidney infection.
Less commonly, a person may develop:
- guttate psoriasis
Some of these can become life-threatening. If new symptoms appear or if symptoms persist or worsen, a person should return to their doctor.
Good hygiene is the best way to reduce the risk of impetigo.
Tips for preventing impetigo include washing any cuts, scrapes, grazes, or insect bites at once and keeping them clean.
If somebody has impetigo, the following tips can help prevent its spread:
- Wash the affected areas with a neutral soap and running water and cover lightly with gauze, if possible.
- Avoid touching the blisters.
- Keep personal items separate and wash daily at 60° Celsius (140° Fahrenheit) or higher.
- Use gloves when applying ointment and wash hands thoroughly after.
- Keep nails short to discourage scratching.
- Wash the hands often.
- Stay home from school or work until the lesions have dried up or the doctor says the person can return.
Impetigo is a common and highly contagious infection that causes blistering on the skin. It mostly affects children but can occur at any age.
It does not usually lead to complications, but people with a weakened immune system may have a higher risk of severe symptoms.
If a person has impetigo, they should seek medical help to treat symptoms and prevent it from spreading to others.