Impetigo is a highly contagious bacterial skin infection — the classic "school sores" that circle a child's nose and mouth with golden, honey-colored crusts. Here's what it looks like, how it spreads, how it's treated, and when your child can safely go back to school.
Impetigo is a highly contagious bacterial skin infection, usually caused by Staphylococcus aureus and sometimes group A strep. It starts as small red sores or blisters that burst and dry into honey-colored crusts, most often around the nose and mouth. It's commonest in children aged 2–5 and spreads through touch, shared towels and scratched skin. It responds well to antibiotic ointment or, if widespread, oral antibiotics, and kids are generally no longer contagious 24–48 hours after treatment begins.
Impetigo — sometimes called "school sores" — is a superficial infection of the top layer of skin. The usual culprit is Staphylococcus aureus, a bacterium many of us carry harmlessly on the skin or in the nose; group A streptococcus causes a smaller share of cases, and the two can infect together. The bacteria get in through tiny breaks in the skin — a scratch, an insect bite, an eczema patch — then multiply and produce the characteristic sores.
It's most common in children between 2 and 5 years old, because young kids have close physical contact, frequent minor skin injuries and imperfect hygiene. But impetigo is not just a childhood disease: adults catch it through contact sports, shared gym equipment, shaving nicks or simply caring for an infected child. It's one of the commonest skin infections worldwide and peaks in warm, humid weather.
The classic form — non-bullous impetigo — accounts for most cases. It begins as small red sores or fragile blisters, usually around the nose and mouth but also on the hands, arms or legs. The sores quickly burst, weep a clear or cloudy fluid, and dry into the unmistakable honey-colored or golden crusts that give the infection its signature look. Nearby lymph nodes may swell, but fever is uncommon. If you're wondering what impetigo looks like at the very start, picture a cluster of red, slightly weepy spots that scab over with a thick amber glaze within a day or two.
Two less common forms exist. Bullous impetigo produces larger, fluid-filled blisters that stay intact longer before collapsing, often on the trunk, and is caused by a staph toxin. Ecthyma is a deeper version in which the infection erodes through the skin surface into small, punched-out ulcers with a hard crust — it's more likely to scar and more common where hygiene is difficult or skin is chronically damaged.
For a few limited patches, the standard impetigo treatment is a prescription topical antibiotic — mupirocin or retapamulin ointment applied to the sores for about five days. Before applying it, gently soak and wash away the honey crusts with warm water and soap: the medicine works much better on clean skin. Keep towels, washcloths and bedding strictly personal, wash them hot, and keep fingernails short so scratching doesn't seed new patches elsewhere on the body.
When the rash is widespread, keeps spreading despite ointment, or involves ecthyma, a clinician will usually switch to an oral antibiotic. Most impetigo clears completely within seven to ten days of treatment and, unlike ecthyma, rarely scars — although the skin can stay temporarily lighter or darker where the sores were. Untreated, it often still resolves in two to three weeks, but it stays contagious the whole time and occasionally triggers complications, so treatment is worthwhile.
Not sure it's impetigo? Scan the rash — RashScan compares it against 50+ skin conditions in about a minute.
Scan your rash freeMost school and daycare guidance follows the same rule: a child can return 24–48 hours after starting effective antibiotic treatment, provided the lesions can be covered. Until then, impetigo is genuinely contagious, and sending a child in risks an outbreak. Wash the child's hands frequently, don't share towels at home, and cover crusted areas loosely with clothing or a non-stick dressing. If the sores aren't improving after two to three days of treatment, check back with the clinician — the antibiotic may need changing.
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Small red sores or blisters that quickly burst and weep, then dry into the classic honey-colored or golden crusts — usually around the nose and mouth, but anywhere on the face, hands or limbs. A less common form (bullous impetigo) produces larger fluid-filled blisters.
Yes, very. It spreads through skin-to-skin contact and by touching contaminated towels, bedding or toys. Children are contagious until 24–48 hours after starting effective antibiotics, or until the sores have crusted over and healed if untreated.
Limited patches are usually treated with a prescription antibiotic ointment such as mupirocin or retapamulin; widespread impetigo needs oral antibiotics. Gently soaking and removing the honey crusts with warm water and soap helps the medicine reach the skin.
Generally until 24–48 hours after effective antibiotic treatment begins. Without treatment, impetigo remains contagious while the sores are oozing and until they have fully crusted and healed, which can take two to three weeks.
Yes. Although impetigo is commonest in children aged 2–5, adults can catch it — especially through close contact with an infected child, contact sports, or breaks in the skin from eczema, shaving or insect bites. Treatment is the same as for children.
Scan the rash — RashScan helps separate impetigo from cold sores, ringworm and other look-alikes, with clear next steps.
Scan a suspected impetigo rashEducational guidance only — not a medical diagnosis.