Condition

Impetigo

Impetigo is a common bacterial skin infection that sits in the top layer of the skin. It shows up as sores that break open and dry into a golden-yellow crust. It is very contagious, mostly affects children, and clears quickly once it is treated.
Dr. Schwarz, MD · Board-certified dermatologistLast reviewed September 8, 2026
16:9 hero for Impetigo. Never cropped: the tone strip and the corner logo depend on the full frame.

Start here

A honey-colored, stuck-on crust around the nose or mouth, or on a scratched patch of skin, in a child, is impetigo until proven otherwise — alarming to parents, and fast to clear with treatment. What I spend most time on is that impetigo nearly always sits on top of something else, usually a scratched bite, a graze, a cold sore, chickenpox or a patch of eczema, so a child who keeps getting it needs the eczema treated properly rather than a stronger antibiotic.

The other thing worth saying plainly: this has nothing to do with being unwashed. The bacteria live on ordinary healthy skin and in healthy noses, and they only cause trouble when they get through a break in the surface.

— Dr. Schwarz, Board Certified Dermatologist

Key Facts

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How commonThe most common bacterial skin infection in children worldwide
Who gets itMostly children between about 2 and 5 years old, though anyone can get it. More common in warm, humid weather
Curable or managedCurable. It clears completely and does not stay in the body
Prescription neededUsually. A prescription cream is enough for a few small patches; widespread infection needs tablets or liquid
Time to improveCrusting starts to settle within a few days of treatment, and most cases clear in about 7 to 10 days

What It Is

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Impetigo is a bacterial infection of the outermost living layer of skin, so it stays shallow and usually heals without scarring. Two bacteria cause almost all of it: Staphylococcus aureus, behind most cases, and Streptococcus pyogenes, the same bacterium that causes strep throat. Both live harmlessly on skin and in the noses of large numbers of healthy people, and only cause trouble once they get through a break.

Non-bullous impetigo, the common variant, starts as small red or brown spots that turn into fragile blisters. They break almost at once, leaving a shallow weeping sore that dries into the golden, honey-colored crust. It sits around the nose and mouth, on the hands, or wherever skin was already broken.

Bullous impetigo comes from a toxin made by certain strains of Staphylococcus aureus. The toxin splits the top layers of skin apart, so instead of small sores there are larger, floppy blisters of clear or cloudy fluid. They break to leave a flat, shiny raw area with a rim of peeling skin and often no crust. It is more common in babies and young children, on the trunk, in skin folds and around the diaper area.

A deeper form, ecthyma, punches into the layer below and leaves a punched-out ulcer under a thick crust. It heals slowly and can scar.

Impetigo is highly contagious — by skin contact and through towels, clothing, bedding and toys — and fingers carry it from one part of the body to another.

Symptoms

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Honey-colored scabs

Crusted

Sores that break quickly and dry into a golden-yellow crust, most often around the nose and mouth in children. It spreads by touch to other spots and other people. It usually clears fast once treated.
Larger fragile blisters

Blistering

Larger, floppy blisters that leave a shiny raw base when they break, more common in babies and young children. The blisters are painless but the skin under them is tender. Nappy and armpit areas are common sites.
Infected eczema or bites

On Top of Another Rash

Golden crusting appearing over an existing rash such as eczema, scabies or scratched insect bites. Skin that suddenly weeps and crusts on top of a known rash has usually become infected. This changes the treatment needed.

How It Looks by Skin Tone

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Golden-yellow crusts below one nostril and at the corner of the mouth on light skin. The skin around each sore is clearly red, and two smaller crusted spots sit on the chin.Golden-yellow crusts below one nostril and at the corner of the mouth on medium olive-toned skin. The skin around each sore is dusky pink to light brown, and two smaller crusted spots sit on the chin.Golden-yellow crusts below one nostril and at the corner of the mouth on brown skin. The skin around each sore is a deeper brown-violet rather than red, and two smaller crusted spots sit on the chin.Golden-yellow crusts below one nostril and at the corner of the mouth on deep brown skin. The skin around each sore is barely darker than its surroundings rather than red, with two smaller crusted spots and one flat darker mark on the chin.
LightMediumBrownDeep

On deeper skin tones the surrounding inflammation is often not red. It looks brown, violet, gray, or just slightly darker than nearby skin, so looking for redness will mislead you. The dependable features are the same on every skin tone: the moist weeping sore, the stuck-on golden crust, and new patches appearing over a few days.

With the color cue weaker, impetigo gets mistaken for eczema for longer than it should, and steroid cream does not treat a bacterial infection. If a patch of eczema starts weeping, crusting yellow, or spreading in a way it never did, ask whether it is infected instead of increasing the steroid. Afterward, flat dark or pale marks are common where each sore was. That is post-inflammatory pigment change, not remaining infection, and it can take weeks to months to even out - longer on deeper skin tones. It needs no antibiotic. Daily sunscreen on exposed areas, especially the face, helps the marks fade and keeps them from deepening. Because impetigo so often develops on top of eczema, and eczema is common and frequently undertreated in people with deeper skin tones, repeated episodes are a good reason to have the eczema reviewed properly.

Where It Shows Up

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Front view of a head with red marks around the nose, on the upper and lower lip, at both corners of the mouth, on the chin and on both cheeks.
Around the nose and mouth
The classic place, because the bacteria are carried in the nose and fingers do the rest. Honey-colored crust around the nostrils and the mouth in a child is the picture most people know.
Front view of a whole body with red marks on both hands and forearms, on both knees and shins and across the abdomen.
Any broken skin
Impetigo starts wherever the skin was already open, so it can turn up anywhere: a scratched bite, a graze, a patch of eczema. Hands, arms and lower legs come next after the face. The blistering form is more often on the trunk, in skin folds and around the nappy area in babies.

What Happens in the Skin

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This is what is going wrong under the skin, in the order it happens. Click a step to see it.

How Impetigo happens
Skin basics
BARRIEREPIDERMISDERMIS0NORMAL SKIN1A BREAK OPENS THE SKIN2BACTERIA GET THROUGH3THE SKIN REACTS4A HONEY-COLORED CRUST FORMS

Healthy skin is a sealed sheet. Bacteria live on top of it all the time and cause no trouble while it stays closed.

A scratch, an insect bite, a cold sore or a patch of eczema opens the surface. The break is often too small to notice.

Staph or strep bacteria that were already sitting on the skin move into the opening. Impetigo is ordinary bacteria in the wrong place, not a sign of dirty skin.

The area turns red and sore as the immune system arrives. Small blisters form just under the top layer, and they break easily.

Fluid from the broken blisters dries into a gold, honey-colored crust. That crust is full of bacteria, which is how it spreads to other spots and to other people.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Three things have to happen. First, the bacteria have to be there. Staphylococcus aureus and Streptococcus pyogenes are carried harmlessly by many healthy people, often in the nose, and hands move them onto skin all day.

Second, the skin has to be broken. Intact skin is an excellent barrier and impetigo rarely starts through it. The break can be tiny — a scratched bite, a graze, a cut, cracked skin at the corner of the mouth, a cold sore, chickenpox spots, scratched eczema. Warm, humid weather and sweat soften the surface and make small breaks likelier, which is why impetigo has a season.

Third, the bacteria multiply there. In non-bullous impetigo the immune response makes the fluid, the weeping and the crust. In bullous impetigo, certain strains of Staphylococcus aureus release a toxin that splits the skin layers apart, so the blister comes from the toxin, not the immune reaction.

Spread is then mechanical and fast. Scratching carries bacteria under the fingernails to new sites, and contact, shared towels, bedding, clothing, sports equipment and toys carry it to other people - which is why it works through a family, a class or a team.

Risk Factors

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Impetigo is about broken skin and close contact, not hygiene.

Broken skin
Eczema
The most important underlying condition. Scratched, broken skin is the entry point, and eczema carries more Staph aureus than healthy skin.
Broken skin
Any break in the skin
Insect bites, grazes, cuts, burns, chickenpox, cold sores, scabies, cracked lips.
Broken skin
Scabies or head lice
Hard scratching, and impetigo follows.
Close contact
Crowded settings
Households with several children, daycare, schools, camps.
Close contact
Contact sports
Wrestling, rugby and judo, with skin contact and shared mats.
Close contact
Shared items
Towels, bedding, clothing, razors, sports equipment.
Age & weather
Age 2 to 5
The peak age by a wide margin - close play, shared surfaces, small skin injuries.
Age & weather
Warm, humid weather
Cases rise in summer and hot climates.
Other health conditions
Nasal carriage of Staphylococcus aureus
Long-term carriers are why impetigo keeps returning around the nostrils.
Other health conditions
Diabetes and a weakened immune system
More likely, more widespread, slower to clear.

Course

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Impetigo moves fast - it appears over days and, treated, clears in about a week. Untreated it usually resolves in around 2 to 3 weeks, but it spreads much further meanwhile, stays contagious throughout, and carries more risk of complications. Ecthyma, the deeper form, takes several weeks and does scar.

Days 1 to 3After the skin breaks
Small spots at the site

Small red, brown or violet spots appear, often around the nose and mouth or on a scratched bite. They itch slightly and get mistaken for a graze or cold sore.

Around the nose and mouthA scratched bite
Days 2 to 5Blistering
Thin blisters that break almost at once

The spots become thin, fragile blisters that break as soon as they form. In bullous impetigo they are larger, floppier and last longer.

Days 3 to 7Crusting
The most contagious stage

The sores weep and dry into a thick, stuck-on golden crust. New patches appear nearby or wherever fingers carried it.

Nearby skinAnywhere the fingers carry it
Within 24 to 48 hours of antibioticsTurning
Spread stops and contagiousness ends

Spread stops, the weeping settles, and after about a day of treatment the person is no longer considered contagious. Most schools use that as the point of return.

Days 7 to 10 of treatmentClearing
Crusts lift and the skin underneath is intact

Crusts lift and the skin underneath is intact. Non-bullous impetigo almost never scars. A flat pink, brown or pale mark can stay for weeks to months, especially on deeper skin tones. Not infection.

What Makes It Better & Worse

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Impetigo is not one problem, it is four — a break in the skin, bacteria getting in, multiplying, and spreading to new sites and people. Impetigo that keeps coming back is almost never an antibiotic problem. Usually it is untreated eczema, an unnoticed source, or hands and towels moving it around the house.

What is driving yours?

FATBARRIEREPIDERMISDERMIS

A scratch, an insect bite, a cold sore or a patch of eczema opens the surface. The break is often too small to notice.

Staph or strep bacteria that were already sitting on the skin move into the opening. Impetigo is ordinary bacteria in the wrong place, not a sign of dirty skin.

What helps

  • Treat the underlying skin problem This prevents the next one.

What makes it worse

  • Untreated or undertreated eczema Scratched skin is the entry point.
  • Scratching Opens fresh breaks, carries bacteria on.
  • Picking off the crusts Reopens the sore, loads the fingers.
  • Scabies, head lice or insect bites Untreated, they keep breaking skin.

What helps

  • Soaking off the crusts gently The ointment reaches the sore.
  • Wash gently with soap and water Twice a day, clean cloth.
  • Ask about persistent nasal carriage Ointment inside the nostrils can help.

What makes it worse

  • Warm, humid conditions and heavy sweating Soften the skin; bacteria establish easily.

What helps

  • A prescription antibiotic ointment Mupirocin, for small patches.
  • Oral antibiotics when it is widespread Many patches, fast spread, or feeling unwell.

What makes it worse

  • Stopping antibiotics early Finish the course or it returns.
  • Using a steroid cream alone Treats the redness, not the infection.

What helps

  • Short fingernails and clean hands Limits the spread.
  • Cover the sores loosely A light non-stick dressing.
  • Own towel, flannel and bedding One each, washed hot.
  • Keep away from school and sport Until about 24 hours of treatment.

What makes it worse

  • Sharing towels, bedding and clothing The main household route.
  • Close contact before treatment starts Nursery, school and sport spread it fast.
  • Leaving weeping sores uncovered They load every surface.

How These Treatments Work

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Treatments for Impetigo do not all work in the same place. Tap one to see where it acts.

Pick a treatment
Skin basics
BARRIEREPIDERMISDERMISKILLS THE BACTERIAKILLS THE BACTERIATAKES THE BACTERIA AWAYCLOSES THE DOOR

A cream is enough for a few patches, and it barely crosses intact skin, so it stays where the infection is.

For widespread impetigo, or when a cream has not worked. The same bacteria, reached from the inside instead.

The crust is full of bacteria, and the cream cannot reach through it. A warm, damp cloth lifts it so the treatment lands on skin.

Eczema, a bite or a scratch is usually how it started. Treating that is what stops it coming back.

The outer film of dead cells and oil. It holds water in and keeps irritants out, and it is thinner than a sheet of paper. Almost every dry, itchy, stinging skin problem starts here.

The outer layer, and the only one anything in a jar reaches. It renews itself constantly: a cell made at the bottom takes about a month to reach the surface and flake off. Most of what a skincare product does, it does here.

The living layer underneath, holding the blood vessels, the nerves and the collagen. It is where lasting change happens and it is hard to reach: most of what is sold for the skin never gets this far.

Over-the-Counter Products

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Everything here you can buy without seeing anyone.

Soaking the crusts off
Soaking the crusts off
Limited evidence
A clean cloth soaked in warm water, held on the crust for a few minutes until it softens, then lifted gently. It is not a treatment on its own, but the ointment cannot reach the sore through a thick crust, so it makes the treatment work. Never pick a dry crust off — that reopens the sore and puts bacteria on the fingers. Use a fresh cloth each time and wash it hot.
A white cream tube lying on its side on a white background, with a plain white label reading Antiseptic Cream and a yellow swoosh beneath it.
Shop antiseptic creams
Weak evidence
General antiseptic ointments from the shelf are not the same thing as a prescription antibiotic ointment and usually do not clear impetigo. The main cost of trying them is time: the infection keeps spreading and the child stays off school for longer than they needed to.

Prescriptions

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These need a prescription.

16:9 hero for Mupirocin. Never cropped: the tone strip and the corner logo depend on the full frame.Diagram: how Mupirocin works in the skin
Strong evidence
The usual first choice for a small number of patches, applied three times a day for about five days after the crust has been softened off. For a few sores it works as well as tablets and avoids their side effects. It is also the ointment used inside the nostrils when impetigo keeps coming back and long-term carriage in the nose is the reason.
A white cream tube lying on its side on a white background, with a plain white label reading Fusidic Acid and a blue swoosh beneath it.
Fusidic acid
Strong evidence
An equally effective alternative ointment for a few small patches, used three times a day for five to seven days. Which of the two you are given depends mostly on local resistance patterns and what your country prescribes first. Neither is enough on its own once the infection is widespread.
A white cream tube lying on its side on a white background, with a plain white label reading Ozenoxacin and a blue swoosh beneath it.
Ozenoxacin cream
Moderate evidence
A newer antibiotic cream for the crusted form, used twice a day for five days. It is an option where resistance to the older ointments is a problem, and it works against some resistant staph. It is not widely stocked and is usually the more expensive choice.
A white cream tube lying on its side on a white background, with a plain white label reading Steroid Cream and a blue swoosh beneath it.
Steroid cream on its own
Never use
A steroid cream calms redness and itch but does nothing to bacteria, so used alone on impetigo it lets the infection carry on. This matters most where impetigo has landed on a patch of eczema and the steroid is already in the house. In that situation both problems are treated, with the antibiotic doing the work on the infection.
An amber prescription bottle lying on its side on a white background with a plain white label reading Antibiotics, and six small round white tablets spilled out in front of it.
Flucloxacillin or cephalexin
Strong evidence
The usual tablets or liquid when the infection is widespread, spreading fast, blistering, or the person feels unwell. A course runs about seven days, and the contagious period ends after roughly the first day of it. Finish the course even once the crusts have gone, because stopping early is one of the common reasons it comes straight back.
A white metal tube lying at an angle on a white background, white ribbed cap to the left, labeled Clindamycin in black lettering with a teal swoosh curving beneath the word.Diagram: how Clindamycin works in the skin
Moderate evidence
Used when there is a penicillin allergy, or when a swab shows resistant staph. It works well against the bacteria that cause impetigo. It upsets the stomach more than the first-choice options and, uncommonly, can cause a serious bowel infection, so any diarrhoea during or shortly after a course is worth reporting.
An amber prescription bottle lying on its side on a white background with a plain white label reading Doxycycline, and six small round white tablets spilled out in front of it.Diagram: how Doxycycline works in the skin
Moderate evidence
Reserved for adults and older children when a swab shows resistant staph, and not used in young children or in pregnancy — ask your doctor if either applies. It is a reasonable option for the age group that fits it, but for the usual patient with impetigo, a small child, it is not the drug.

Procedures

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These are done in the office, usually over several visits.

No procedures listed yet.

When to See a Dermatologist

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Treat this rather than wait it out — treatment cuts the contagious period to about a day, stops it running through a household or a class, and lowers the risk of complications. Get seen when sores weep and dry into stuck-on golden crusts, particularly around the nose and mouth or on a patch of eczema, since a few small patches usually need only a prescription ointment. Go back sooner if there are many patches or fast spread, large blisters or skin peeling in sheets, a fever, no change after two to three days of treatment, repeated episodes, or sores turning into deep, punched-out ulcers. Get same-day care if the surrounding skin becomes swollen, hot and increasingly painful with redness or darkening spreading outward, and treat a newborn with blistering or peeling skin, or anyone with a suppressed immune system, as urgent.

— Dr. Schwarz, Board Certified Dermatologist

Complications

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Cellulitis

Occasionally the bacteria get past the top layer and into the deeper tissue. The area around the sores becomes swollen, hot and increasingly painful, with redness or darkening spreading outward into normal skin, and the person often feels unwell with it. It is uncommon and it is treatable, but it needs antibiotic tablets rather than a cream, and it is a same-day problem rather than one to watch overnight.

Ecthyma — the deeper form

When the infection punches through into the layer below, it forms a punched-out ulcer under a thick, hard crust, most often on the lower legs. It is the one form of impetigo that heals slowly and does leave a scar. It is more likely where sores have been picked at, where treatment was delayed, and in people with diabetes or a weakened immune system. It needs antibiotic tablets, not an ointment.

Days off school and spread at home

Most settings ask for about 24 hours of antibiotic treatment before a child returns, with any remaining sores covered, so treating early is what gets them back soonest. The bigger cost is usually at home: without separate towels, bedding and hot washing, it works its way through the other children and sometimes the adults, and each new person starts the clock again.

Lookalikes

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Eczema

This is the confusion that matters most, because it runs in both directions. Eczema is dry, itchy and thickened, and it comes and goes in the same places. Impetigo weeps and dries into a stuck-on golden crust, and it spreads to new spots within days. Very often the answer is both at once: impetigo sitting on a scratched patch of eczema. If a familiar eczema patch suddenly starts weeping, crusting yellow or spreading in a way it never did, that is a reason to ask about infection rather than to increase the steroid cream.

Cold Sores

Both sit around the mouth, both blister and both crust, so they are mixed up constantly — and a cold sore is also one of the breaks that impetigo starts in. A cold sore is a tight cluster of small blisters in one spot on or beside the lip, it tingles and burns before it appears, it stays put, and it comes back in the same place again and again. Impetigo spreads to new spots over days, its crusts are thicker and honey-colored, and it does not recur in one fixed site.

Ringworm

A ringworm patch can crust and flake at the edge and is often treated as impetigo for a week before anyone questions it. The shape is what separates them: ringworm is a round patch with a raised, scaly, advancing rim and a flatter, clearer center, and it grows slowly outward over weeks. Impetigo has no ring, its crust is thick and golden and sits over a moist sore, and it moves to new sites in days. It matters, because an antibiotic does nothing for ringworm and a steroid cream makes it worse.

Myths

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  • "Impetigo means the child is dirty." It does not. The bacteria live on healthy skin and in healthy noses. What is needed is a break in the skin, usually an insect bite, a graze or eczema. Clean, well cared for children get impetigo constantly.
  • "The golden crust is the infection healing." The crust is dried fluid full of bacteria - the most contagious part, not a sign of healing. Softening it off gently so the ointment reaches underneath is part of treatment.
  • "It will scar." Ordinary impetigo sits in the top layer of skin and almost never scars. Flat pink, brown or pale marks fade over weeks to months. The exception is ecthyma, the deeper ulcerating form - and picking makes scarring likelier in any form.
  • "You can just leave it and it will go." It usually does resolve in a couple of weeks, but meanwhile it spreads across the body and to other people. Treatment cuts the contagious period to about a day and lowers the small risk of complications.
  • "Antiseptic cream from the shop will clear it." Over-the-counter antiseptics are not a prescription antibiotic ointment and generally do not clear impetigo. Delaying real treatment mostly delays the child's return to school.
  • "Impetigo can cause rheumatic fever." Skin infection with streptococcus has not been shown to cause rheumatic fever - that follows throat infection. A separate, rare kidney complication, post-streptococcal glomerulonephritis, can follow skin infection, and antibiotics do not reliably prevent it.
  • "It only affects children." Children are the main group by far, but adults get it too - usually after an injury, with eczema, in contact sports, or in warm humid conditions.

Questions Patients Ask

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How long is it contagious?

Until about 24 hours after antibiotics start, or until the sores have fully dried and crusted if untreated, which takes far longer. That is why treatment is offered even though it would clear on its own - it cuts the contagious period from a week or more to about a day.

When can my child go back to school or nursery?

Most settings ask for around 24 hours of antibiotic treatment first, with remaining sores covered. Rules vary between countries, schools and nurseries, so check the policy.

Will it leave a scar?

Ordinary impetigo almost never scars, because it sits in the top layer of skin. Flat pink, brown or pale marks fade over weeks to months, more slowly on deeper skin tones. Ecthyma, the deeper ulcerating form, does scar, and picking raises the risk in any form.

Why does my child keep getting it?

Usually eczema that is not fully controlled, which keeps supplying broken skin. Other reasons are scratching from bites or scabies, shared towels and bedding, or long-term Staphylococcus aureus in the nose. Look at those rather than repeat the antibiotic.

Can adults catch it from their child?

Yes, though it is much less common in adults with healthy skin. The risk rises with eczema, a cut, a graze or any other break. Separate towels, handwashing after applying the ointment, and hot washing of bedding reduce the chance.

Should I use a cream or tablets?

It depends how much skin is involved. A prescription ointment works as well as tablets for a few patches and avoids the side effects of oral antibiotics. Tablets or liquid are for widespread infection, rapid spread, large blisters, or an unwell child. Make that call with a doctor.

References

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