Impetigo: Pictures, Symptoms, Treatment & How Long It Is Contagious
Impetigo is a superficial bacterial infection of the skin, usually caused by Staphylococcus aureus or Streptococcus pyogenes. It produces blisters and sores that break and dry into a distinctive honey-coloured crust, and it spreads easily by touch — which is why it is most common in young children and in households, nurseries and sports teams.
Medically reviewed by Dr. Celina Kazumi Iwasa, MD · Last reviewed 2026-08-23
Quick answer
Impetigo is a contagious bacterial skin infection that begins as small red sores or blisters, most often around the nose and mouth, which burst and dry into golden-brown honey-coloured crusts. It is treated with topical antibiotic cream for localised patches or oral antibiotics if widespread. People are usually no longer contagious 24–48 hours after starting antibiotics, or once the sores have fully crusted and healed.
What impetigo looks like
There are two patterns. Non-bullous impetigo — around 70% of cases — starts as tiny blisters that rupture within hours, leaving a moist red base that dries into the classic golden crust. Bullous impetigo forms larger fluid-filled blisters that stay intact longer before collapsing into a flat brown scab with a collarette of scale.
Common locations
- Around the nose, mouth and chin (most common site in children)
- Hands, forearms and lower legs
- Nappy area and skin folds in infants (often bullous)
- Over existing eczema, insect bites, cuts or cold sores
- Scalp and behind the ears
Typical signs
- Honey-coloured or golden-brown crusts that look stuck on
- Small blisters or pustules that burst quickly and weep
- Sores that enlarge and multiply over a few days
- Mild itch or soreness, but usually no fever in simple cases
- Swollen lymph nodes near the affected area
On brown and Black skin
On brown and Black skin the surrounding inflammation may look brown, violet or grey rather than red, so the golden crust is the most reliable sign. Marks left behind after healing can be darker or lighter for several months, but impetigo itself does not scar unless the sores are deep.
Causes and triggers
Impetigo happens when Staphylococcus aureus or Streptococcus pyogenes enters through a break in the skin barrier. Anything that damages the barrier — a scratch, a bite, eczema or a cold sore — creates the entry point, and warmth and humidity help the bacteria multiply.
| Trigger | Why it matters |
|---|---|
| Broken skin | Cuts, grazes, insect bites, scratched eczema and cold sores are the usual entry points (this is called secondary impetigo or impetiginisation). |
| Direct contact | Skin-to-skin contact spreads the bacteria between children, siblings and contact-sport teammates. |
| Shared items | Towels, bedding, clothing, flannels and toys can carry bacteria between people in the same household. |
| Warm humid weather | Impetigo is most common in summer and in warm climates, when skin is moist and more often broken. |
| Crowded settings | Nurseries, schools, gyms and residential care make transmission easier. |
| Nasal carriage of staph | Many people carry S. aureus in the nostrils; scratching or nose-picking transfers it to broken skin nearby. |
Conditions that look similar
The golden crust is characteristic, but several conditions can produce crusted sores and are treated very differently.
| Condition | How to tell it apart |
|---|---|
| Cold sores (herpes simplex) | Grouped small blisters in the same spot each time, preceded by tingling; crusts are usually darker and the border is not expanding outward. |
| Infected eczema | Widespread itchy eczema with weeping and crusting on top — often both conditions are present at once and both need treating. |
| Ringworm (tinea) | Round patch with a raised scaly border and clearer centre; scaling rather than golden crusting. |
| Chickenpox | Crops of itchy blisters at different stages across the whole body with fever, not clustered around the mouth. |
| Scabies with secondary infection | Intense night-time itch with burrows between fingers, plus crusting where the skin has been scratched raw. |
Treatment options
Impetigo is treated with antibiotics and simple hygiene measures. Most cases clear within 7–10 days on treatment, and much of the value of treatment is in stopping the spread to other people.
Topical antibiotics
For a few localised patches, a prescription topical antibiotic such as fusidic acid or mupirocin, applied for around five days, is usually first line. Some regions use topical hydrogen peroxide 1% cream for very mild cases to reduce antibiotic use.
Oral antibiotics
Widespread impetigo, bullous impetigo, or infection that is not improving on topical treatment usually needs a course of oral antibiotics such as flucloxacillin (or a macrolide if penicillin-allergic).
Crust removal and hygiene
Soak the crusts with warm water and gently remove them so the cream reaches the skin underneath. Wash hands after every application, keep fingernails short, and do not share towels, flannels or bedding.
Reduce spread
Cover sores with a loose dressing where practical. Children should stay off nursery or school until 48 hours after starting antibiotics, or until every sore has crusted over and dried.
Treat the underlying cause
If impetigo has developed on top of eczema, scabies or bites, that condition must be treated too — otherwise the infection keeps returning to the same broken skin.
When to see a doctor
Impetigo almost always needs prescription treatment, so see a clinician promptly rather than waiting. Seek urgent care if there are signs the infection is going deeper.
Red flags
- Fever, feeling unwell, or spreading redness and swelling around the sores
- Sores that are getting deeper, painful or turning into ulcers (ecthyma)
- No improvement after 3–5 days of prescribed treatment
- Impetigo in a newborn, or in anyone immunosuppressed or with diabetes
- Dark urine, facial puffiness or joint pains in the weeks after infection
Frequently asked questions
What does impetigo look like?
Impetigo starts as small red sores or blisters, usually around the nose and mouth, which burst within hours and dry into golden-brown honey-coloured crusts that look stuck onto the skin. Patches enlarge and multiply over a few days and may be surrounded by mild redness or darkening.
How long is impetigo contagious?
Impetigo is contagious from the appearance of the first sore until the sores have fully crusted and dried, or until 24–48 hours after starting antibiotic treatment. Most schools and nurseries ask children to stay home for that first 48 hours of treatment.
How do you get rid of impetigo fast?
The fastest route is prescription treatment: a topical antibiotic for localised patches or oral antibiotics if it is widespread. Alongside that, soak and gently remove crusts before applying cream, wash hands after every contact, and change towels and bedding daily. Most cases clear in 7–10 days.
Can adults get impetigo?
Yes. Adults commonly develop impetigo on top of eczema, shaving rashes, insect bites or cuts, and in contact sports such as rugby and wrestling. It is less frequent than in children but the treatment is the same.
Does impetigo leave scars?
Simple impetigo heals without scarring because the infection is superficial. Temporary darker or lighter marks are common, particularly on deeper skin tones, and usually fade over weeks to months. Deep ulcerated impetigo (ecthyma) can scar.
Is impetigo the same as a cold sore?
No. Cold sores are caused by the herpes simplex virus and recur in the same spot with tingling before grouped small blisters appear. Impetigo is bacterial, spreads outward across the skin and produces golden crusts. They can look similar early on, and a clinician can distinguish them.
Not sure if it is impetigo?
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Check your skin nowRelated guides
- Impetigo: full clinical A–Z entry
- Eczema (atopic dermatitis)
- Folliculitis
- Skin rash types: identify a rash by pattern
- Skin symptom pictures library
This page is for general information and does not replace a medical consultation. If you are worried about a skin change, see a qualified clinician.