Impetigo (School Sores)
A common, very catchy skin infection from staph or strep bacteria. Sores often start around the nose and mouth, burst and leave honey-coloured crusts. Mostly in children, easily treated, and not a sign of a dirty house.
What it looks like. Small blisters or red sores that weep, then form yellow-brown crusts, usually on the face, arms or legs. A blistering type (bullous impetigo) causes larger blisters on the body. It often starts in skin that’s already broken: eczema, insect bites, scabies, head lice scratches or cuts. On brown and black skin, sores may look darker or purple-grey rather than red, and can leave dark marks that fade over months.
Diagnosis is usually by look; a swab is sometimes taken if it isn’t healing or keeps coming back. In Australia, school sores are extremely common in some remote Aboriginal and Torres Strait Islander communities, where untreated strep skin infection is linked to kidney inflammation and rheumatic fever. Treating it promptly matters.
The impetigo ladder
Small patches: clean, cover, ointment. Lots of sores or feeling unwell: tablets. Always look for what broke the skin first.
- Step 1 · Self-careClean, soften, coverWash gently with soap and water, soak off crusts, pat dry and cover with a waterproof dressing. Keep nails short.
- Works
- Not tested alone in trials; helps the treatment work and cuts spread
- Cost
- About $5–10 for dressings
- How long
- Until the sores have healed
- Watch for
- Don’t share towels, bedding or bath water.
Covered sores don’t go to school on someone else’s fingers.
- Step 2 · PrescriptionAntibiotic ointment (mupirocin)For a few small patches. Apply after cleaning.
- Works
- About twice as many cured as with a dummy treatment; about as good as tablets for limited impetigo
- Cost
- Under the $25 PBS co-payment
- How long
- Usually about 5–7 days, as directed
- Watch for
- Don’t keep using leftover tubes later: bacteria become resistant.
Squeezed on for a week, not a month. Resistance is real.
- Step 3 · PrescriptionAntibiotic tablets or liquid (cefalexin, flucloxacillin; trimethoprim-sulfamethoxazole in some remote communities)For widespread sores, the blistering type, fever, or when ointment hasn’t worked.
- Works
- Works well for widespread impetigo; more stomach side effects than ointment
- Cost
- Under the $25 PBS co-payment
- How long
- Usually 5–7 days; finish the course
- Watch for
- Diarrhoea, rash. Tell your doctor about any penicillin allergy.
Tastes terrible. Works anyway.
- Step 4 · GPTreat what’s underneathScabies, eczema, head lice or bites that keep breaking the skin.
- Works
- Repeat impetigo often stops once the itch behind it is treated
- Cost
- Varies
- How long
- Weeks
- Watch for
- Repeat infections can also mean staph is living in the nose: ask about this.
Fix the leaky roof, not just the puddle.
Save your money
Popular, heavily marketed or often asked about, but the evidence is weak or says no.
- Antiseptic creams and washes aloneAntibiotic ointment did better than antiseptics in trials. Fine for cleaning, not a cure.
- Tea tree oil, honey and other home remediesNo good trials for impetigo. Meanwhile it keeps spreading.
- Leftover antibiotic cream from last timeOften the wrong cream, and repeated use breeds resistance.
What you can do
- Keep children home until 24 hours after starting antibiotics, and cover any sores on exposed skin when they go back.
- Wash hands with soap after touching sores; hot-wash towels, clothes and bedding.
- Keep sores away from newborn babies.
- Treat eczema, scabies and lice so the skin can heal.
See your GP if
- You think it’s impetigo: most need prescription treatment
- Sores are spreading or not better after a week of treatment
- It keeps coming back
- The person has diabetes or a weakened immune system
See a doctor the same day for fever or feeling unwell, spreading red, hot or painful skin, any skin infection in a newborn, or puffy eyes, cola-coloured urine or much less urine in the weeks after school sores (possible kidney inflammation).
Common questions
How long is impetigo contagious?
Until 24 hours after starting antibiotics, or until the sores have dried and crusted over if not treated.
When can my child go back to school or childcare?
In Australia, after at least 24 hours of antibiotic treatment, with any sores on exposed skin covered.
Can adults get impetigo?
Yes, though it’s much more common in children. Adults often get it on broken skin, such as eczema or a shaving rash.
Will it scar?
Usually not. Darker marks can stay for a few months, especially on brown or black skin, but they fade.
Helpful resources
- Staying Healthy (NHMRC): ImpetigoOne-page sheet from Australia’s childcare infection guide, covering exclusion and preventing spread. Free.
- NSW Health: Impetigo fact sheetPlain guide to treatment, school exclusion and hygiene. Free.
Evidence and more information
- Healthdirect: Impetigo
- NSW Health: Impetigo (school sores)
- Cochrane: Interventions for impetigo
- MJA (2020): Skin infections in Australian Aboriginal children
maladywise.com/impetigo/