Intro

Cold sore stages

A form of the herpes simplex virus called HSV-1 causes cold sores. Also known as fever blisters, cold sores usually form on or around the lips and typically progress through five stages, ending in a blister stage.

An untreated cold sore usually lasts 7-10 days, but can remain for up to two weeks. It typically progresses through five distinct stages.

Learn more about cold sores

Find out more about herpes labialis

Day 1

Tingle Stage

The first stage of a cold sore, this is when you'll feel those first few symptoms. It typically only lasts for a couple of hours. Your skin could feel tight and itchy, and is your body’s way of responding to the HSV-1 infection.

Hover over the lips to view an enlarged image of this stage.

TIPS

It’s best to start treatment at the first tingle.

What are the first symptoms on your mouth or lips?

Pain or burning

Soreness or tenderness

Pain or burning: You most likely have cold sore.

Soreness or tenderness: This is usually minor and can be the first sign of a spot.

TIPS

It’s best to start treatment at the first tingle.

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Days 2-4

Blister Stage

The next stage in the cold sore cycle is when you first see the blister developing. It is full of fluid containing millions of virus particles. You’ll probably see a group of small, painful lumps that may multiply or grow. The surrounding skin may become red and swollen.

Hover over the lips to view an enlarged image of this stage.

TIPS

Cold sores are contagious even after developing a blister.

Where are the blisters?

Inside my lips

Outside my lips

Inside: You might actually be experiencing a canker sore. These tend to appear as a sore, or tender white or yellow patch. They can be found under the tongue, inside the cheeks or lips, or on the gums or roof of the mouth. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

Outside: It is very likely this is a cold sore. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

One: If the blister is fairly firm, it is more likely to be a blemish Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

Cluster: If you have a cluster of small, softer blisters filled with clear fluid, it is more likely to be a cold sore. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

Clear. Cold sores are generally clear, as they are full of fluid. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

Coloured. Pimples aren’t clear. They tend to be red and/or yellow as they contain skin oils and bacteria. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

TIPS

Cold sores are contagious even after developing a blister.

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Day 4

Ulcer Stage

This can be the most painful stage as the blisters burst and a shallow ulcer (open sore) develops. You may also see a red ring of inflammation around the affected area.

Hover over the lips to view an enlarged image of this stage.

TIPS
This stage can be very painful.

Where is the redness on your lips?

Large area

Specific spot

Large spot: The redness is not centered around a specific spot. Intense dryness can extend beyond the lip with irritation, pain and possibly splitting or bleeding. If this is the case, you probably have chapped lips. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

Large spot: It’s likely you have a cold sore rather than chapped lips as cold sores usually appear in clusters. Please ask a pharmacist if you’re unsure whether you have a cold sore or not.

TIPS

This stage can be very painful.

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Days 5-8

Scabbing Stage

This is when your cold sore dries out and forms a yellow/brown scab. Underneath the scab, healing of the sore takes place. As your scab shrinks, it may leave you with painful cracks that are prone to bleeding. You may also experience itching and burning.

Hover over the lips to view an enlarged image of this stage.

TIPS

Don’t peel off the scab as you could damage the new, delicate skin and may leave a scar. Let the scab fall off naturally.

Don’t forget to keep using Zovirax for at least 4 days but no longer than 10 days.

TIPS

Don’t peel off the scab as you could damage the new, delicate skin and may leave a scar. Let the scab fall off naturally.

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DAYS 8-10

Healing Stage

As your scab starts to come off, you may notice some dry flaking and residual swelling. Your skin may also remain slightly pink or red.

Hover over the lips to view an enlarged image of this stage.

TIPS

If your cold sore persists for longer than 10 days, consult your healthcare professional for advice.

TIPS

If your cold sore persists for longer than 10 days, consult your healthcare professional for advice.

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