When comparing impetigo vs herpes, the key point is that impetigo is a bacterial skin infection that often causes honey-coloured crusts on the face, especially around the nose and cheeks, while herpes usually means cold sores caused by the herpes simplex virus, which tend to appear as grouped blisters along the lip border.
They can look similar at a glance, but they need different treatment: impetigo may require antiseptic or antibiotic treatment, while cold sores may be treated with antiviral medicines.
For adults in the UK trying to work out which facial infection they may be dealing with, getting that distinction right matters because the wrong treatment can delay recovery and increase the risk of passing it on. This guide compares impetigo vs cold sores across symptoms, causes, how each condition develops, treatment options, how to reduce spread, when to seek medical advice, and the key differences to look for.
Key things to know
- Cold sores are caused by the herpes simplex virus type HSV-1; impetigo is a bacterial skin infection.
- Cold sores begin with a tingling or burning sensation before clustered blisters appear on or near the lip.
- Impetigo causes sores that can develop a honey-coloured crust, often on the face.
- Aciclovir is used for cold sores, while impetigo may require antiseptic or antibiotic treatment.
What Causes Each Condition
Cold sores are caused by the herpes simplex virus (usually HSV-1), a viral infection that remains dormant in the body between outbreaks and can be triggered by stress, illness, sun exposure, or a weakened immune system.
Impetigo is a bacterial skin infection, most often caused by Staphylococcus aureus or streptococcus bacteria, and is highly contagious through direct contact or touching contaminated surfaces. This difference in cause is exactly why the two need different treatment approaches; one is viral, the other bacterial, and no single medicine treats both.
Once you have had a cold sore, the virus stays often in the same area, in an (inactive) dormant state in nerve tissue, which is why outbreaks can recur throughout life at the same general site.
Unlike impetigo, the cold sore virus stays dormant between flare-ups; impetigo is an active bacterial infection that, once properly treated, does not leave a dormant reservoir behind in the same manner, though reinfection from a new bacterial source is possible.
Other Conditions That Can Look Similar
Cold sores and impetigo aren't the only conditions that can cause facial blisters or sores. Angular cheilitis (cracking at the corners of the mouth), certain allergic reactions, and other skin conditions that can look similar can sometimes be mistaken for one or the other.
This is part of why a confident self-diagnosis is not always straightforward, and why a pharmacist or GP's opinion is genuinely useful if you are not sure whether it is impetigo or a cold sore, rather than a sign you should have been able to work it out yourself.
Location and Appearance
Cold sores predominantly affect the lip area and immediately surrounding skin. They begin as small, fluid-filled blisters that cluster together, typically appearing on the lip border or just above the upper lip. Some people notice a burning sensation before the visible blisters appear. The blisters are clear to slightly cloudy and sit on reddened skin.
Impetigo can appear anywhere on the face, including around the nose, cheeks, and mouth area, and isn't limited to the lip border the way cold sores typically are. It starts as impetigo sores or small red sores that quickly develop into larger, pus-filled blisters. These blisters burst easily, leaving sores covered by a honey-coloured crust that is one of impetigo's most recognisable features.
If you are trying to tell the two apart visually, location is one of the more useful early clues: sores confined tightly to the lip border are more likely a cold sore, while broader affected areas across the face, especially with a golden, crusted appearance, point more toward impetigo.
How Each Condition Progresses
| Cold sore | Impetigo | |
|---|---|---|
| Early sign | Tingling or itching sensation. | Small red spots. |
| Development | Blisters develop after the initial tingling or itching. | Sores or blisters can develop and then break, leaving crusts. |
| Distinctive feature | Clustered, fluid-filled blisters. | Honey-coloured or golden crusts after blisters burst. |
| Typical duration | 7 to 10 days. | Usually improves with appropriate treatment. |
| Spread risk | Contagious, especially when blisters are present. | Highly contagious, can spread to other areas through scratching. |
Reducing Spread While You Have Either Condition
- Avoid touching the affected area unnecessarily, and wash your hands thoroughly if you do
- Avoid sharing towels, cutlery, cups, or lip products, including lip balms, while symptoms are present
- Avoid kissing or skin to skin contact until a cold sore has fully healed
- Keep impetigo covered where practical, keep broken skin clean and covered when practical, and avoid scratching, which spreads the bacteria to new areas
- Children with impetigo should stay away from school or nursery until all sores have crusted and healed, or for 48 hours after antibiotic treatment has started.
Both impetigo and cold sores can spread through close personal contact, but both conditions are contagious in different ways, cold sores primarily through direct contact with the blister fluid, impetigo through both direct contact and touching contaminated surfaces or objects. Taking sensible precautions reduces the risk to people around you while you are affected.
Cold Sore Treatment
Antiviral medication works best when started early, ideally at the first tingling sensation, before blisters fully form. Aciclovir tablets, taken at first symptoms, may help reduce how long an outbreak lasts and how severe it is. Antiviral creams such as aciclovir cream, applied regularly through the day, can also help, particularly for milder or more localised outbreaks.
Valaciclovir is another antiviral option, sometimes preferred for its dosing schedule. People treating cold sores may also use over the counter medications such as ibuprofen for pain relief.
Starting treatment promptly matters more for cold sores than many people realise, because early treatment gives antivirals the best chance of working.
Antiviral treatment is most effective when started early, although some aciclovir products can still be started during the blister stage.
Impetigo Treatment
Impetigo may require antiseptic or antibiotic treatment, depending on its extent and severity. Mild, localised impetigo is often treated with an antibiotic ointment such as fusidic acid, and antibiotic creams are also commonly used for small areas of infection.
More extensive infections may need oral antibiotics, such as flucloxacillin. Unlike cold sores, Impetigo usually improves with appropriate treatment.
Antiviral treatments like aciclovir have no effect on impetigo, since they target viral replication, not bacteria, which is exactly why getting the diagnosis right before starting treatment matters.
Completing the full course of antibiotics, even once the crusts have cleared and skin looks improved, matters for the same reason it matters with any bacterial infection. Follow the prescribed course and treatment instructions, even if the impetigo starts to clear.
Why the Distinction Matters
Using the wrong treatment does not just fail to help, it delays getting the right one started. Antiviral cream won't clear a bacterial infection, and prompt treatment helps prevent impetigo from spreading further. If you are not confident which condition you are dealing with, that is exactly the kind of situation worth getting a professional opinion on rather than guessing and starting whichever treatment you already have at home.
This matters even more when children are involved. Impetigo especially affects children in close-contact settings such as school or nursery, and a delayed or incorrect treatment choice can mean a longer period of contagiousness.
H2: When to Seek Medical Advice
- You are not certain which condition you have.
- Cold sores are frequent, severe, very painful, or affect the eyes.
- Impetigo symptoms are spreading rapidly, especially in a child or anyone with a weakened immune system.
- Symptoms do not improve with appropriate treatment, or seem to be getting worse.
- You develop a fever, body aches, or feel generally unwell alongside the skin symptoms.
Cold sores affecting the eye area need prompt attention specifically, since this can involve the eye itself and needs different management than a typical outbreak.
Impetigo in children, or anyone with a weakened immune system, also warrants faster attention given how easily it spreads.
A pharmacist is often a good first point of contact if you are unsure, and can advise whether you need a GP appointment or whether an over-the-counter or prescription option is appropriate.
In some cases, a clinician may take a skin swab, particularly if impetigo keeps coming back.
If you think you are dealing with a cold sore, start your free cold sore consultation to get assessed and access antiviral treatment quickly.
Available Cold Sore Treatments
| Treatment | Price from |
|---|---|
| Aciclovir tablets | £12.99 |
| Aciclovir 5% cream | £8.99 |
| Valaciclovir | £18.99 |
| Valtrex | £34.99 |
Prices are updated regualrly and may change. These treatments are for cold sores specifically; if you have impetigo, an antibiotic from a GP or pharmacist is the appropriate treatment instead.
Quick Symptom Checklist
Cold sore, more likely if these are the key symptoms:
- A tingling or burning sensation came first, before any visible spot.
- Sores are confined to the lip border or just above it.
- Blisters are clustered and fluid-filled, not pus-filled.
- You have had similar outbreaks in the same spot before.
Impetigo, more likely if:
- Sores appeared elsewhere on the face, not just the lip.
- You noticed pus-filled blisters that burst and left a honey coloured crust.
- Someone in close contact with you has or recently had impetigo.
- The area seems to be spreading rapidly.
This checklist is a starting point for your own thinking, not a diagnostic tool. If several signs point in different directions, or you are still unsure, that's exactly when a pharmacist or GP's assessment adds real value.
Medical Disclaimer
This guide provides general information to help distinguish between impetigo and cold sores. It is not a substitute for personalised medical advice, diagnosis, or treatment, as these symptoms can resemble other skin conditions and may sometimes require professional assessment. Visual differences described here are general patterns, not a definitive diagnostic tool, and some cases can be less clear-cut than a typical textbook presentation. If you are not certain which condition you have, or if symptoms are severe, spreading, or affecting a child or immunocompromised person, seek medical advice for a proper diagnosis rather than self-treating based on this guide alone, especially if you are unsure whether it is impetigo or cold sores. If you have questions about your specific symptoms, speak to your prescriber, pharmacist, or GP.
