Cold Sores Patient Guide
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Developed by the dermatologists of Skin Care Guide

How do I know that I have a cold sore?

How do I know that I have a cold sore?
Think you might have a cold sore? The information below might be helpful in identifying one.

Location of the herpes outbreak

Cold sores are most frequently located on the lips at the place where the lips meet the skin and the mucosa (see images).
These herpes outbreaks can also be found occasionally on the cheek, chin and nose.
In individuals who have their immune system suppressed by medications or infections such as HIV/AIDS, the herpes outbreaks can also appear in the mouth and can sometimes be seen as chronic superficial ulcers.

Has it occurred in the same place before?

Herpes simplex infection is the most common cause of a rash that recurs in the same place or location on the skin.
There is another condition that produces a recurring rash in the same location and this is much less common and is called a Fixed drug eruption. This is an allergic reaction that manifests or shows itself only in a small local outbreak whenever the drug is taken.

Tingling, itching, burning? Pay attention to the clues.

There are symptoms that some people can recognize that indicates that a cold sore is on its way.

Between 46% and 60% of people notice symptoms 24 hours or less before the actual appearance of cold sores. You may notice symptoms such as inflammation, itching, burning/tingling, and altered sensations at the area where the sores will form.*
These are called prodrome or prodromal symptoms.


It is important to cold sore sufferers to be aware of these symptoms as they allow early intervention or treatment that could abort or shorten the duration of the outbreak. There is usually a specific cycle of events in the life cycle of a cold sore. The entire process generally lasts for 10-14 days.