How long is impetigo contagious?

Untreated, impetigo stays contagious for as long as there are open, oozing, or crusted sores. Once antibiotic treatment is under way, it stops being contagious much sooner — usually within the first day or two of treatment. Follow your doctor's guidance and your school's or daycare's return policy, keep the sores covered, and don't share towels or bedding in the meantime.

Can adults get impetigo?

Yes. Impetigo is most common in young children, but adults can catch it too — especially through close contact with an infected child, in contact sports, or when bacteria get into already-broken skin such as eczema, insect bites, or shaving nicks. It's treated the same way, and the same keep-it-covered rules apply.

Usually not. Impetigo sits in the very top layer of the skin, so the sores typically heal without scarring once treated, though a patch of temporary darker or lighter skin can linger for a while, especially in deeper skin tones. Scratching and picking are what raise the risk of scarring and of spreading the infection to new spots — keep nails short and the sores covered.

Impetigo, Explained (The Honey-Crusted Rash Kids Bring Home)

Impetigo is one of the most common bacterial skin infections in young children — and one of the most contagious. Its calling card is a cluster of sores that ooze and then dry into honey-colored crusts, most often around the nose and mouth. It looks alarming and it spreads easily through a classroom or a household, but here's the reassuring part: it sits in the very top layer of the skin, it's very treatable, and it usually heals without scarring (StatPearls; AAD).

What it is

Impetigo is a superficial bacterial infection of the outermost skin, caused by Staphylococcus aureus ("staph"), group A Streptococcus ("strep"), or both (StatPearls). The bacteria get in through small breaks in the skin — a scratch, an insect bite, a patch of eczema, a scraped knee — and multiply in the top layer.

It's most common in children around ages 2 to 5, and it thrives where skin-to-skin contact is constant: daycares, schools, sports teams, and within families. Warm, humid weather and crowded conditions make it more likely (StatPearls).

It spreads by touch — directly from the sores, or indirectly via towels, bedding, clothing, and toys. Scratching a sore and then touching another body part is also how a single spot becomes several.

What it looks like

There are two main forms (StatPearls; AAD):

Non-bullous impetigo (the common one, roughly 70% of cases). Small red sores or pimple-like bumps that quickly burst and ooze, then dry into the classic golden, honey-colored crust. Favorite spots: around the nose and mouth, and on the arms and legs. It may itch, but the child usually feels otherwise well.
Bullous impetigo. Caused by a staph toxin that makes the skin layers separate, producing soft, fluid-filled blisters that pop easily and leave a shiny, raw-looking ring. More common in infants and on the trunk, in skin folds, and in the diaper area.

A deeper, ulcerated version called ecthyma punches below the surface and looks like "punched-out" sores with thick crusts — that form is more serious and always needs a doctor.

Lookalikes matter here. Crusted patches can also be cold sores, eczema that has become infected, or ringworm — one reason a proper look from a clinician is worth it, especially the first time.

How it's treated

Impetigo is one of skin medicine's genuinely satisfying fixes — the right antibiotic clears it reliably (AAD):

A few spots: a prescription antibiotic ointment (such as mupirocin) applied to the sores. Over-the-counter antibiotic ointments are generally not enough — the prescription ones target these bacteria specifically.
Widespread sores, bullous impetigo, or ecthyma: an oral antibiotic course.
Gentle care: soaking off loose crusts with warm water before applying ointment helps it reach the bacteria; keep the area clean and covered with gauze or a loose bandage.

Two rules that do a lot of work: finish the full course even when it looks healed, and go back to the doctor if it isn't clearly improving within a few days — occasionally the bacteria are resistant (including MRSA) and the prescription needs switching.

Stopping the spread at home

Cover the sores and wash hands after every touch or ointment application.
Don't share towels, washcloths, bedding, razors, or clothing; wash them in hot water.
Keep nails short and discourage scratching — that's the main way it spreads across one body and to other people.
Keep kids home from school or daycare until the doctor says they're no longer contagious — typically once treatment has been under way for a day or two and per your school's policy.

When to see a doctor

Impetigo should be seen by a clinician for diagnosis and a prescription — this isn't a wait-it-out rash. Be prompt if:

The redness starts spreading, swelling, or becoming warm and painful (possible cellulitis — a deeper infection).
There's fever, or your child seems unwell rather than just itchy.
Sores look deep or "punched-out" (possible ecthyma), or keep coming back.
The urine turns dark or cola-colored in the weeks after strep impetigo — a rare kidney complication (post-streptococcal glomerulonephritis) that needs medical attention (StatPearls).

For the bigger picture of rash red flags, see When Is a Rash an Emergency?

Because impetigo is contagious, moves fast, and mostly affects young children, it's a doctor's-visit condition, not an app question. A dermatrix.life skin assessment reads uploaded photos for slow, stable skin concerns in adults and is informational only, never a diagnosis — crusted, spreading sores on a child belong with a pediatrician or family doctor who can examine them and prescribe the right antibiotic.