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Is it a Cold Sore?

You look in the mirror and see something unusual on your lip. Or maybe a spot on your lip feels painful, even though you don't see anything there. Now you're wondering, "Is it a cold sore?" It could be. Let's go through the possibilities.

A cold sore is caused by the herpes simplex 1 virus, not to be confused with herpes simplex 2, which is the most common cause of STI genital herpes. If you've had cold sores before, then you already have the virus in your body.

Once you've had it, the virus doesn't go away - instead it stays in the body "sleeping" until stress or some other trigger causes it to "wake up", resulting in a new cold sore developing.

If you've had a cold sore before, and you've recently been exposed to any of these triggers (illness, stress, sunlight/UV light, very cold temperatures), that spot you see may be a cold sore.

If you haven't had a cold sore before, but you've recently had contact with someone with a cold sore or shared things like, cups, silverware, razors, toothbrushes, lip balm or lipstick with them, then you may have just picked up the virus and this is your first outbreak.

If it is a cold sore, it often begins with a tingle on the lip that can turn into a red bump, which can then become a blister or group of blisters. Normally the blister will pop and the cold sore will begin to scab over for a number of days. The average cold sore lasts between 7-12 days.

What if it’s not a cold sore? There are some other options.

It could just be a pimple. If you normally get pimples and they hurt before they appear, this is a possible explanation.

It could also be a bacterial skin infection called impetigo. This is more common in children than adults though. If it is impetigo, it would have started from an open wound or even a minor scratch which then got infected and turned into a big, oozy blister. Impetigo is usually treated with prescription antibiotics. If you believe you or your child may have impetigo, consult your doctor.

The last option is that it could be a genital herpes blister. This is possible if you've recently had oral sex with a partner with genital herpes. If you are concerned you may have a genital herpes blister, consult your doctor.