Impetigo is a common, highly contagious bacterial skin infection that mainly affects infants and young children, especially those between the ages of 2 and 5. It causes small red sores that quickly break open, ooze, and dry into a distinctive honey-colored crust, most often around the nose and mouth. Impetigo can look startling to parents and spread quickly among siblings, classmates, or daycare groups, but it is rarely serious and almost always clears up completely with the right care. Because outbreaks are common wherever young children play in close contact, recognizing the sores early and starting treatment promptly helps limit how far the infection spreads. This guide explains what impetigo is, its symptoms, causes, how it is diagnosed, the treatments available, and the latest research.
What is impetigo?
Impetigo is a superficial bacterial infection of the outer layer of the skin. It is caused by Staphylococcus aureus, Streptococcus pyogenes (also known as group A strep), or a combination of the two, and it ranks among the most common skin infections of early childhood. The bacteria take hold in the top layers of skin, usually after the skin’s protective barrier has already been broken in some way, and multiply to produce the sores that give impetigo its name.
More than 3 million cases are diagnosed in the United States each year, and while impetigo can affect people of any age, it shows up most often in young children, particularly those in daycare or elementary school where close physical contact is routine. There are two main forms: non-bullous impetigo, which makes up roughly 70 percent of cases and is sometimes called impetigo contagiosa, and bullous impetigo, which accounts for about 30 percent of cases and is more common in infants and younger children. Both forms respond well to treatment, and impetigo does not usually leave lasting marks on the skin once it clears.
Symptoms of impetigo
The most familiar sign of impetigo is a small cluster of red sores, often around the nose and mouth, though they can also appear on the hands, arms, and legs. In non-bullous impetigo, the most common form, these sores rupture quickly and ooze a clear or yellowish fluid that dries into a distinctive honey-colored, or golden, crust, typically within about a week. Bullous impetigo instead produces larger, fluid-filled blisters that can look more dramatic but tend to be less crusty; this form is more common in infants and younger children and is sometimes mistaken for other skin problems.
Itching and mild soreness around the sores are common, and because scratching easily carries bacteria to other parts of the body, new patches often crop up on skin the child has touched after scratching. Impetigo does not usually come with fever or feeling unwell, so if a child does seem sick, or if redness and swelling spread well beyond the crusted area, it is worth having a doctor check for a deeper infection.
What causes impetigo and its risk factors
Impetigo develops when Staphylococcus aureus or group A strep bacteria enter the skin through a small break in its surface, such as a cut, scrape, or insect bite. These bacteria commonly live on the skin and in the nose without causing any problems, but once they get past the skin’s outer barrier, they can multiply and trigger the sores typical of impetigo. Skin that is already irritated or broken offers an especially easy opening, which is why children with chickenpox, cuts, or other conditions that disrupt the skin surface are more likely to develop this kind of secondary infection.
Eczema is one of the most common examples of this pattern in children, since scratching the itchy, inflamed patches repeatedly breaks the skin and lets bacteria in. Keeping the itchy, inflamed skin of eczema as calm and intact as possible is one practical way to close off that entry point. Other factors that raise the chances of impetigo include warm, humid weather, crowded settings such as daycare, school, or contact sports, and close skin-to-skin contact or sharing items like towels, clothing, or sports equipment, all of which make it easy for the bacteria to pass from one child to another.
How impetigo is diagnosed
Impetigo is almost always diagnosed simply by looking at the skin. A doctor or nurse practitioner recognizes the condition from the appearance and location of the sores, especially the honey-colored crusts that follow a ruptured blister, and most cases need no laboratory testing at all. Telling the two main forms apart helps set expectations for how the sores will look and heal.
| Type of impetigo | Typical features |
|---|---|
| Non-bullous impetigo | About 70% of cases; small red sores that rupture and dry into honey-colored crusts, usually around the nose and mouth |
| Bullous impetigo | About 30% of cases; larger, fluid-filled blisters caused by toxin-producing Staphylococcus aureus; more common in infants and young children |
A bacterial swab or culture of a sore is not usually needed for a typical case, but a doctor may take one if the sores are widespread, keep coming back, fail to improve after three to five days of treatment, or appear during a household, daycare, or team outbreak, since a culture can identify the exact bacteria involved and check for antibiotic resistance. If redness, warmth, or swelling spreads beyond the crusted sore itself, or a child develops a fever, a doctor may also order a complete blood count, and checking the neutrophil count on a blood test can help show whether the infection has become a deeper problem such as cellulitis rather than impetigo alone.
Treatment options for impetigo
Treatment for impetigo focuses on clearing the bacterial infection and keeping it from spreading to other skin or other people. For limited impetigo, with just one or a few small sores, a topical antibiotic applied directly to the skin is usually enough and tends to clear the sores within about a week.
| Approach | Role |
|---|---|
| Topical antibiotics (mupirocin, retapamulin, ozenoxacin) | First-line treatment for limited, localized sores; applied directly to the skin several times a day |
| Oral antibiotics (cephalexin, dicloxacillin) | Used for widespread, numerous, or bullous sores, or when a topical antibiotic has not helped within three to five days |
| Gentle wound care | Soaking or washing crusted sores and loosely covering them supports healing and helps prevent spread |
| Hygiene measures | Washing hands, avoiding shared towels or clothing, and trimming nails limit spread to other skin and other people |
Which option fits best depends on how much skin is involved and how the sores look. Topical antibiotics such as mupirocin and retapamulin have long been the standard choice for mild, localized impetigo, and ozenoxacin is a newer topical option with similar effectiveness. Oral antibiotics work throughout the body and are generally reserved for more extensive or bullous impetigo, or for sores that do not respond to a topical antibiotic alone. Finishing the full course of whichever antibiotic is prescribed, even after the sores look better, helps clear the infection completely and reduces the chance that the bacteria become harder to treat the next time.
Living with impetigo and long-term outlook
Most children recover from impetigo completely within a week or two of starting treatment, with no lasting marks on the skin. Because impetigo spreads so easily, the practical side of managing it often matters as much as the medicine: keeping sores loosely covered, washing hands frequently, avoiding shared towels, washcloths, or bedding, and keeping fingernails short all help stop the infection from reaching new skin or other family members. Most guidance suggests children can return to school or daycare about 24 hours after starting an antibiotic, once the sores are drying up or can be kept covered, though it is worth checking your own school or daycare’s specific policy.
Serious complications from impetigo are uncommon, especially with prompt treatment and a completed course of antibiotics. In rare cases, an infection that goes untreated or does not respond to treatment can spread deeper into the skin and become cellulitis, marked by expanding redness, warmth, swelling, or fever, or, less commonly, lead to a kidney condition called post-streptococcal glomerulonephritis that can follow a strep infection of the skin. Good hygiene, prompt treatment, and finishing the full antibiotic course are the best ways to avoid these outcomes and keep impetigo a short-lived, manageable illness.
Latest scientific advances in impetigo research
According to PubMed-indexed research, a 2025 meta-analysis pooling four randomized controlled trials with 754 patients found that ozenoxacin 1% cream significantly improved clinical success compared with placebo and reduced both clinical and microbiological treatment failure, with effectiveness comparable to mupirocin (Tuesta et al., 2025). What this means for you: ozenoxacin has solid evidence behind it as a topical option, giving families and clinicians another well-supported choice alongside mupirocin for treating limited impetigo.
Other recent research explains why using antibiotics carefully, and only when needed, matters for keeping impetigo easy to treat. A 2025 genomic surveillance study analyzing 317 bacterial samples across Europe identified a spreading strain of resistant Staphylococcus aureus, nicknamed FAR-MRSA, that resists both methicillin and fusidic acid and is increasingly causing impetigo and other skin infections in young children (Roer et al., 2025). What this means for you: resistant staph strains are a real and growing contributor to childhood impetigo, part of why doctors reserve culture testing for sores that are severe, recurrent, or slow to improve. A 2024 surveillance study in Belgium adds a related warning: resistance to mupirocin, one of the most widely used topical antibiotics, rose from under 2 percent to as much as 5.6 percent of bacterial isolates between 2013 and 2023, with up to about 10 percent of pediatric isolates resistant to both mupirocin and fusidic acid by the end of that period (Yin et al., 2024). What this means for you: because the two most commonly used topical antibiotics can lose effectiveness within the same bacterial strain, finishing the prescribed course and returning to a doctor if sores are not improving within a few days helps make sure a resistant infection is caught and treated appropriately rather than left to spread.
Glossary of key impetigo terms
| Term | Definition |
|---|---|
| Impetigo | A common, contagious bacterial infection of the top layer of skin, most frequent in young children. |
| Non-bullous impetigo | The most common form of impetigo, with small sores that rupture and form honey-colored crusts. |
| Bullous impetigo | A form of impetigo with larger, fluid-filled blisters, most common in infants and young children. |
| Honey-colored crust | The golden, dried covering that forms over a ruptured impetigo sore. |
| Staphylococcus aureus | A common bacterium that lives on the skin and causes most cases of impetigo. |
| Group A strep | Short for Streptococcus pyogenes, a bacterium that can cause impetigo alone or together with staph. |
| MRSA | Methicillin-resistant Staphylococcus aureus, a staph strain resistant to certain common antibiotics. |
Frequently asked questions about impetigo
Is impetigo contagious, and how does it spread?
Yes, impetigo is highly contagious. It spreads through direct skin-to-skin contact and by sharing items that have touched infected skin, such as towels, clothing, bedding, or sports equipment. This is why it can move quickly through households, daycare groups, and classrooms, and why keeping sores covered and avoiding shared items helps limit how far it travels.
How long is impetigo contagious after starting antibiotics?
Impetigo is generally considered contagious until the sores are healing or can be kept fully covered. Most guidance suggests a child can be around others, and typically return to school or daycare, about 24 hours after starting an antibiotic, though some guidance allows this as early as 12 hours. Without treatment, impetigo can remain contagious for much longer, sometimes until the sores clear on their own.
What does impetigo look like, and why does it form honey-colored crusts?
Impetigo typically starts as small red sores or blisters, often around the nose and mouth, that quickly rupture and ooze. As the fluid dries, it forms a distinctive honey-colored, or golden, crust, usually within about a week. This crusted appearance is one of the most recognizable features of impetigo and is often enough for a doctor to diagnose it on sight.
Can impetigo go away on its own without antibiotics?
Mild, limited impetigo sometimes clears on its own over a few weeks, but treatment with a topical or oral antibiotic is generally recommended because it speeds healing, reduces the chance of spreading the infection to other skin or other people, and lowers the small risk of complications. Because impetigo is so contagious, most doctors advise treating it rather than waiting it out.
What’s the difference between bullous and non-bullous impetigo?
Non-bullous impetigo is the more common form, making up about 70 percent of cases, and produces small sores that rupture quickly and form honey-colored crusts. Bullous impetigo, caused by toxin-producing Staphylococcus aureus, makes up about 30 percent of cases and produces larger, fluid-filled blisters that are less likely to crust over. Bullous impetigo is more common in infants and younger children.
When can my child return to school or daycare with impetigo?
Many schools and daycare programs allow children to return about 24 to 48 hours after starting antibiotic treatment, provided the sores are drying up or can be kept covered with a bandage or clothing. Because policies vary, it is worth checking with your child’s school or daycare directly, and keeping sores covered in the meantime helps protect classmates regardless of the exact timeline.
Sources
- Centers for Disease Control and Prevention — Clinical Guidance: Impetigo — CDC, 2024 — cdc.gov
- MedlinePlus, National Library of Medicine — Impetigo — MedlinePlus, 2024 — medlineplus.gov
- American Academy of Dermatology — Impetigo: Diagnosis and Treatment — AAD, 2023 — aad.org
- Tuesta BL et al. — Ozenoxacin 1% in Pediatric and Adult Patients with Impetigo: A Meta-Analysis of Randomized Trials — Journal of Clinical Medicine, 2025 — doi.org/10.3390/jcm14072157
- Roer L et al. — Spread of the FAR-MRSA clone, a fusidic acid- and meticillin-resistant Staphylococcus aureus ST121, Europe, 2014 to 2024 — Eurosurveillance, 2025 — doi.org/10.2807/1560-7917.ES.2025.30.28.2500452
- Yin N et al. — Emergence and spread of a mupirocin-resistant variant of the European epidemic fusidic acid-resistant impetigo clone of Staphylococcus aureus, Belgium, 2013 to 2023 — Eurosurveillance, 2024 — doi.org/10.2807/1560-7917.ES.2024.29.19.2300668
Further reading
- Understand a deeper skin infection that can follow an untreated case in this guide to the symptoms and treatment of cellulitis.
- Build confidence reading test results with this guide to reference ranges, flags, and next steps on a lab report.
Understand your lab results with BloodSense
Impetigo itself is diagnosed by looking at the skin, not with a blood test, but lab work can still play a supporting role when an infection looks like it is spreading or is not responding to treatment as expected: a bacterial culture identifies exactly which bacteria are involved and whether they are resistant to common antibiotics, while a complete blood count and neutrophil level can help show whether the body is fighting a more significant infection. Seeing where a value falls against its reference range, and understanding what a flag actually means, makes lab results far easier to act on with your child’s pediatrician. BloodSense translates a full lab report into plain language, showing what each marker means so you can follow along with confidence whenever testing becomes part of the picture.
