In short
The honey-coloured crust around a child's nose and mouth is a bacterial skin infection that spreads through touch. Treatment clears it quickly, and it stops being contagious 48 hours after treatment starts.
Emergency if: Spreading redness with heat and pain, fever with a child who is unwell in themselves, or a rapidly worsening skin infection — seek emergency care now.
On your report
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On this page
01
What it looks like
Impetigo is a very contagious but usually not serious skin infection, most common in young children, particularly between about two and six. It starts as red sores or blisters — the redness is harder to see on brown and black skin — which burst quickly and dry into crusty, golden-brown patches often described as looking like cornflakes stuck to the skin.
It favours the face, especially around the nose and mouth, and the hands. The patches can itch, are sometimes sore, and spread outward. A less common form produces larger fluid-filled blisters that ooze and leave a scaly rim; this is bullous impetigo and it is caused by a particular bacterial toxin.
02
Where it comes from
The culprits are ordinary skin bacteria — staphylococcus and streptococcus — which live harmlessly on many people and cause trouble when they get past the skin's surface. That is why impetigo usually appears on skin that was already damaged: a cut, a scratch, an insect bite, eczema, or scabies.
It spreads by direct skin-to-skin contact and by touching contaminated things — towels, bedding, toys. This is why it runs through a household and a classroom so efficiently, and why treating the skin without changing the towels tends to be followed by a second round.
03
Treatment
Most localised impetigo is treated with something applied to the skin: an antiseptic cream such as hydrogen peroxide, or an antibiotic cream. Tablets are used when the infection is widespread, when creams have not worked, for the bullous form, or for babies and people with a weakened immune system, where the aim is to head off more serious problems.
Finish the full course even once the crusts start clearing, because stopping early is the usual reason it returns. Depending on local rules, a pharmacist may be able to advise on or treat impetigo in a child over twelve months. See a doctor instead for a baby under a year, if you are breastfeeding and the sores are on the breast, if the immune system is weakened, if treatment is not working, or if impetigo keeps coming back.
04
How long it is catching
This is the question every parent and employer actually wants answered. Impetigo stops being contagious about 48 hours after treatment is started. Without treatment it can take somewhere between one and three weeks — essentially until every patch has healed, dried and crusted over.
For school and nursery the practical rule is to keep a child at home until the sores have crusted over and healed, or for 48 hours after starting treatment. Guidance differs slightly between countries, with some allowing return once treatment has begun provided exposed sores are covered, so follow whatever your own school or workplace uses — and treating promptly is what shortens the exclusion either way.
05
Stopping it spreading at home
Wash the affected areas with soap and water and dry them properly. Wash your hands often, and especially before and after applying cream. Wash flannels, towels, sheets and pillowcases at a high temperature, and clean toys with detergent and warm water. Do not share towels, flannels or bedding while anyone is infected.
Discourage touching and scratching, which spreads the infection to new sites and is the main cause of scarring in an infection that otherwise rarely scars. Skip the gym and contact sports, and do not prepare food for other people. Keep away from newborns and from anyone with diabetes or a weakened immune system until the contagious period has passed.
06
When it is not simple impetigo
With treatment, patches generally clear within about ten days; left alone, healing takes two to three weeks. Marks left behind may be lighter or darker than surrounding skin for a while, but true scarring is uncommon. Impetigo that keeps returning is worth investigating — a swab from the skin and from inside the nose can identify carriage, and an antiseptic wash or nasal ointment may be used to clear it.
A doctor will also want to be sure it is impetigo rather than something else. Cellulitis, which spreads redness and warmth deeper into the skin, needs different treatment. Cold sores, eczema, chickenpox and shingles are all mistaken for it. Get urgent advice if redness is spreading, the area becomes hot and painful, or the child develops a fever and is unwell in themselves.
When to act
Routine — see a doctor
A few golden-crusted patches in a well child over twelve months: a pharmacist or doctor can treat it, and the full course is finished even once it looks better.
Same-day — call promptly
A baby under a year, a weakened immune system, widespread or blistering sores, impetigo that is not improving on treatment, or repeated episodes.
Emergency — act now
Spreading redness with heat and pain, fever with a child who is unwell in themselves, or a rapidly worsening skin infection — seek emergency care now.
Values mentioned in this story
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Sources
- Impetigo — NHSnhs.uk
- Impetigo — DermNetdermnetnz.org
- Impetigo — MedlinePlusmedlineplus.gov
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