Impetigo is the rash most parents recognise the second time they see it. Honey-coloured crust, usually around a 3-year-old's nose or mouth, appearing where there was a scrape or a snotty patch the day before. It is bacterial, very contagious in nursery rooms, and almost always treatable at home once you know what you are looking at. For more on common childhood skin conditions, visit Healthbooq.
What Impetigo Looks Like
It usually starts as a small red sore that turns into a thin-walled blister. The blister breaks within a day or two and dries into the giveaway crust — yellow-gold, slightly shiny, often described as "cornflake" or "honey." Most cases sit around the nose, mouth, or chin in toddlers and preschoolers. The peak ages are 2 to 5.
The infection rarely starts on perfect skin. It almost always lands on a small break — eczema, an insect bite, a scraped knee, the raw skin under a runny nose. Two bacteria do the work: Staphylococcus aureus and Streptococcus pyogenes (Group A Strep), often together.
There is a second form, bullous impetigo, caused by certain Staph strains that produce a toxin which loosens the top layer of skin. You see larger, fluid-filled blisters that can be 1–2 cm across, with a thin, lacquer-like crust after they pop. It is more common in babies under one year and is the form to take seriously in newborns.
Why Some Children Get It and Others Don't
Impetigo is not a hygiene failure. The bacteria live on plenty of healthy children's skin and in their noses; they only cause trouble when they find a way through the barrier.
Three groups are most exposed:
- Children with eczema. The skin barrier is already compromised, and scratching seeds bacteria into open patches. A sudden weeping, crusty flare on top of usual eczema is often impetigo, not "just" worse eczema.
- Toddlers in nursery during cold-and-runny-nose season. The skin under a streaming nose breaks down within days.
- Children with siblings who have it. It moves through a household quickly.
How It Spreads
Direct skin-to-skin contact is the main route — a hand on a sister's face, a wrestling match, a shared cuddle. Indirect spread through towels, flannels, bedding, and shared bath toys is the second route. The bacteria survive on fabric long enough to matter.
Two practical points:
- A child is contagious until 48 hours into antibiotics, or until every sore is fully crusted and dry if you are not using antibiotics.
- Scratching transfers the infection from one part of the body to another. A patch under the nose becomes a patch on the cheek, then on the hand. Keep nails short.
When to See the GP
Most cases are managed by your GP rather than A&E. Worth a same-week appointment when:
- The crusts are spreading day by day, or there are more than a handful of patches.
- The child is under one year old, particularly if you see large bullous-style blisters.
- A child with eczema suddenly develops weeping, crusted, painful patches.
- There is fever, the child is unwell, or the redness around the sores is spreading into the surrounding skin (cellulitis).
A rare but real complication is post-streptococcal glomerulonephritis — a kidney inflammation that can follow strep impetigo a couple of weeks later. If your child develops dark or tea-coloured urine, swollen eyes, or feels unwell after impetigo, mention the recent skin infection and get them seen.
Keeping It From Spreading at Home
You don't need to disinfect the house. You do need a few separations for about a week:
- A separate towel and flannel for the affected child, washed hot.
- Wash bedding and pyjamas every couple of days while crusts are still active.
- Cover sores with a loose dressing where it is practical — particularly on hands and forearms.
- Hand-wash before and after applying creams. Cut fingernails short on the same day you start treatment.
- No shared baths during the contagious window.
Nursery and School
UK guidance from UKHSA: stay home until 48 hours after antibiotics have started, or until all sores are dried and crusted if no treatment is being used. The same broadly applies under CDC and most European guidance — covered, treated, no longer weeping.
Tell the nursery so they can check whether other children are showing early signs. Impetigo tends to ripple through a room rather than appear in one child at a time.
Key Takeaways
Impetigo is a contagious bacterial skin infection that turns small breaks in the skin into honey-coloured crusts, mostly around the nose and mouth. It clears in 7–10 days with topical or oral antibiotics; keep your child off nursery until 48 hours after starting treatment.
