A cold sore is usually a group of small blisters that appear on or around the border of the lip. The blisters are often around 2 to 3 millimetres across. A cold sore often starts with tingling, itching, burning or tightness before the blisters appear. It may then break open, form a crust and gradually heal over around seven to twelve days.
If you have had a cold sore before, a new outbreak may appear in roughly the same area. However, not every lip lesion is a cold sore, so appearance alone cannot confirm what you have.
What a cold sore looks like can change from day to day. That is why it can be more useful to look at the stage, the symptoms and how the area changes over time rather than comparing your skin with one photograph.
Key things to know
- Cold sores usually develop through several stages, so the timing and changes can be useful clues
- Common features include a cluster of small blisters around the lip border, often preceded by tingling or itching
- A healing cold sore often develops a dry yellowish or brownish crust that gradually flakes away
- A pink, brown or darker mark may remain for some time after the sore has healed, and this does not necessarily mean there is a scar
- A first outbreak can look different from a recurring cold sore and may cause symptoms beyond the lips
What Does the Start of a Cold Sore Look Like?
At the very beginning, there may be nothing obvious to see. This is an important part of understanding what a starting cold sore can look like.
The first sign is often a feeling rather than a visible change. You may notice tingling, itching, burning or tightness in one small area several hours before a blister appears. Some people describe it as a persistent itch or a feeling of pressure under the skin.
If there is a visible change at this stage, it may be quite subtle. You might notice slight swelling, a small change in colour or an area that feels a little firmer than the surrounding skin.
This early stage is also when some antiviral treatments may be more useful, as they are generally intended to be started early in an outbreak. The right treatment depends on the medicine and your individual circumstances, so follow the product information or advice from a healthcare professional.
Stage by Stage: What You Actually See
| Stage | When | What it looks like | How it feels |
|---|---|---|---|
| Tingle | Hours before, up to about a day | Usually nothing visible, or slight puffiness and a subtle colour change in one area | Tingling, itching, burning or tightness |
| Blister | Days two to four | A cluster of small blisters, roughly 2 to 3mm each, often filled with clear fluid and surrounded by irritated skin | Tender, tight or sore, especially when moving the mouth |
| Weeping | Days four to five | Blisters may break and leave shallow open areas with a red or irritated base. Several areas may join together | Often sore or painful |
| Crusting | Days five to eight | A yellowish or brownish crust forms over the affected area. It may crack when you smile or eat | Tight, itchy or dry |
| Healing | Days eight to twelve | The crust gradually flakes away, leaving new skin that may look pink, shiny or slightly darker | Usually more comfortable, although some itching may remain |
What Does a Cold Sore Look Like at First?
The first visible stage is usually a group of tiny raised bumps rather than one large blister. They tend to sit close together, often around the border of the lip, and the surrounding skin may look swollen or irritated.
Cold sore blisters are usually small and occur in a group. However, appearance is not enough to confirm that a lesion is a cold sore. A single larger blister on the lip can have other causes, such as a mucocele, burn or friction.
What a Healing Cold Sore Looks Like
A crust often develops as a cold sore heals. It can look more noticeable than the earlier stages, but this does not necessarily mean the cold sore is getting worse.
The crust may be yellowish or brownish and can become dry and cracked as the lip moves. Small amounts of bleeding can happen if the crust cracks.
Try not to pick or peel the crust. Doing so can reopen the area and may slow healing. It can also increase the risk of irritation or infection.
What a Healed Cold Sore Looks Like
Once the crust has come away, the new skin underneath may look pink, shiny or slightly different from the surrounding skin. On darker skin, the area may look brown, greyish or darker than the surrounding skin instead.
This change in colour can happen after inflammation and does not necessarily mean that the area is scarred. It may gradually become less noticeable over the following weeks.
Sun exposure can make changes in skin colour more noticeable, so protecting the lips from the sun may be helpful while the area settles. A cold sore does not usually leave a permanent scar, although picking or repeated irritation can increase the risk of scarring.
How a Cold Sore Looks on Different Skin Tones
Many descriptions of cold sores focus on redness. On brown or black skin, redness can be less noticeable, so it may be more helpful to look for other changes.
On darker skin, you may notice:
- Swelling or a change in the texture of the skin
- A shiny or stretched appearance over the affected area
- The blisters themselves, which may look pale or fluid filled
- A colour change that appears darker, purplish, greyish or ashy rather than bright red
- A darker mark after the sore has healed, which may take some time to fade
The stages of a cold sore are broadly similar across different skin tones. The main difference is that colour changes, particularly redness, may be harder to see on darker skin.
Stages of a Cold Sore: Photos, Pictures and Why They Disappoint
Searches for stages of a cold sore photos, stages of a cold sore pictures and cold sore stages pictures are common. However, photographs can make it difficult to work out whether what you are seeing is similar to your own symptoms.
Online images may show more noticeable or severe examples because these are more likely to be photographed. A typical cold sore can look much smaller or less obvious.
Lighting can also change how the colour of a crust or sore appears. Photographs can also make it harder to judge texture, swelling and how the area has changed over time.
Instead of relying on one photograph, look at the pattern. Did you notice tingling first? Did small blisters then appear? Did they break open before a crust formed? Has the area gradually started to heal?
If you are concerned about a lesion, taking a photograph of your own lip in similar lighting each day may help you keep track of changes. If it does not settle as expected, you can also show the images to a pharmacist or GP.
A First Outbreak Looks Nothing Like a Recurrence
A first infection with herpes simplex virus can look different from the cold sores that some people develop later.
A first outbreak can sometimes cause several painful ulcers inside the mouth, sore or swollen gums, a sore throat, a high temperature or swollen glands in the neck. Children may also become reluctant to eat or drink because their mouth is painful.
This type of first infection is sometimes called primary herpetic gingivostomatitis. If a child has painful mouth sores and is struggling to drink, medical advice is important because dehydration can become a concern.
Adults can also have a first episode, and symptoms can sometimes be more widespread than those seen during later outbreaks.
If the sores are mainly inside the mouth and you also feel generally unwell, it is worth speaking to a GP or another healthcare professional rather than assuming that you have a standard cold sore.
What It Looks Like When It Is Not a Cold Sore
| What you might see | More likely to be | The giveaway |
|---|---|---|
| Cracking and soreness confined to the corners of the mouth | Angular cheilitis | It mainly affects the corners of the mouth rather than forming a cluster on the lip |
| A thick golden crust that looks stuck on and spreads outwards | Impetigo | The crust and spreading pattern can be typical of this bacterial skin infection |
| A single large, soft bump on the inner lip | Mucocele | It is usually a single bump and can occur after biting or damaging the lip |
| A shallow crater with a white or yellow centre and red border | Mouth ulcer | It is usually inside the mouth, whereas cold sores commonly occur on or around the outer lip |
| Small pale bumps that have been present for years | Fordyce spots | They do not usually go through the blistering and crusting stages |
| A red spot with a white centre near the lip | Spot or blocked follicle | It is usually a single lesion and does not typically start with the tingling and blistering pattern of a cold sore |
| Dry, scaly redness around the mouth | Lip licking dermatitis | The irritation often follows the area that is repeatedly exposed to saliva |
Where Cold Sores Appear
Cold sores most commonly appear around the vermilion border, which is the line where the coloured part of the lip meets the surrounding skin.
If you get recurring cold sores, they may appear in roughly the same area each time. This is because herpes simplex virus remains in nerve cells after the initial infection and can reactivate later.
Cold sores can also appear on the skin just above the upper lip, around the corner of the mouth, on the chin or around the nostril. A sore around the nose can sometimes be confused with other skin conditions, including impetigo.
Some locations and situations need medical advice rather than self treatment. If a blister or sore is on or near the eye, seek same day medical advice because herpes infection affecting the eye can be serious. If blisters are spreading across areas of damaged skin in someone with eczema, urgent medical assessment is also recommended.
How Long Each Stage Lasts, and What Is Normal
A typical cold sore may take around seven to twelve days to heal. The exact timing can vary from person to person.
The blistering and weeping stages usually happen earlier in the outbreak, followed by crusting and gradual healing. Some mild outbreaks may be less obvious and may not follow every stage clearly.
A first outbreak can also be different from a recurring cold sore and may last longer or cause more widespread symptoms.
Speak to a healthcare professional if a sore is still open or weeping after around ten days, continues to get larger, is accompanied by a fever, or becomes significantly more painful or swollen after it had started improving. These changes can sometimes happen with a secondary bacterial infection or another condition that needs different treatment.
What to Do Once You Recognise It
If you think you have a cold sore, early treatment may be worth discussing with a pharmacist or healthcare professional, particularly if you regularly get outbreaks. Some antiviral treatments are intended to be started during the early tingling stage, so it is useful to seek advice promptly rather than waiting for the sore to become more noticeable.
You can also take simple steps to protect the area while it heals. Avoid picking or peeling the sore, wash your hands after touching it, and try to prevent the skin from becoming very dry or cracked.
Cold sores can spread through close contact. Avoid kissing and sharing items that touch your mouth while you have an active cold sore. It is particularly important to avoid kissing newborn babies until the cold sore has completely healed, as herpes simplex infection can be serious in newborns.
If your outbreaks are frequent, unusually severe, slow to heal or affecting your eye, speak to a healthcare professional rather than relying on repeated self treatment.
An online consultation with a UK registered prescriber may be one option if you need an assessment and treatment is appropriate.
Medical Disclaimer
This page describes common features of cold sores for general information. It cannot diagnose your symptoms and is not a substitute for an examination by a healthcare professional.
If you are not sure what you are looking at, speak to a pharmacist, GP or dentist rather than assuming that it is a cold sore. Seek same day medical advice for anything affecting the eye or vision, spreading blisters in someone with eczema, or a first episode with fever and difficulty eating or drinking, particularly in a child.
Any lip lesion that has not healed within three weeks should be assessed by a healthcare professional.
Suspected side effects from a medicine can be reported through the MHRA Yellow Card scheme.
