Is It a Pimple or a Cold Sore?

How To Tell the Difference Between a Pimple and a Cold Sore

You wake up one day with a sore, red bump right by your lip.  Is it a cold sore or a pimple?

Although they're completely different skin problems, cold sores and pimples can start off looking very similar.  Early on, it can be tough to tell.

But there are clues to help you distinguish between the two.

Cold Sores Begin with Itchy, Tingly Skin

Cold sores around the mouth.
Photo: Avatar_023 / Getty Images

In the days or hours before a cold sore appears, you may notice your skin itches or tingles.

Cold sores typically appear around the mouth, chin, between the mouth and nose, or on the lip. 

Cold sores are very painful, and can throb and burn.

Pimples Begin as a Tender Spot, or they just Appear

Acne Pustules
Acne Pustules - Photo courtesy of ADAM. ADAM

Before you actually see a pimple, you might feel it.  You may notice a tender area just under the skin.  You might even be able to feel a small lump under the skin.

Often, though, pimple just appear without any warning.  You go to sleep one night and wake up with a big zit.  

Pimples can happen anywhere on the face or body.  They can develop on the border between the lip and skin, but never directly on the lip.  If your sore is directly on the lip, it's a cold sore rather than a pimple.

Big pimples are also painful, but they don't burn.

Cold Sores Develop Clusters of Tiny Blisters

Cold sore blisters
Photo: ibusca / Getty Images

A good way to determine the difference between a pimple and a cold sore is by its appearance.  Cold sores develop clusters of tiny blisters.  If you look carefully at the picture on the left, you can see these blisters.

Eventually, the blisters burst and can ooze fluid.  The cold sore will scab over, crack and ooze, and slowly heal over the next 10 or so days.

Pimples Develop a White Head

Pimple with a white head
Photo: Angela Palmer

Instead of blisters, pimples develop a white head.  The picture on the left clearly shows a white head in the middle of the red bump.

Most pimples have just one, but I've seen massive zits that have developed several heads.  They don't look like blisters, though.

Cold Sores are Caused by the Herpes Simplex Virus

Pimples and cold sores develop differently too.  Cold sores are caused by a virus: herpes simplex 1 (HSV-1).

This virus is super common.  It's estimated that 50-80% of people have the virus, although it doesn't always cause breakouts.

HSV-1 is contagious.  You can get it from kissing someone with a cold sore, or eating or drinking off the same utensils. 

Pimples are Caused by Blocked Pores and the Propioni acnes Bacterium

Pimples, on the other hand, develop when there is a blockage of the pore.  Bacteria (Propioni acnes) invade, and a inflamed pimple is formed. 

Unlike cold sores, acne is not contagious.  You can hug, kiss, share lip balm, with someone with a pimples and never get a pimple yourself.

Here's How You Can Treat a Cold Sore

You never want to touch a cold sore.  Because the virus that causes cold sores is contagious, touching your sore makes it easier to spread it to other people (and other areas of your own body).

Don't try to pop the blisters, either.  It won't help the sore to heal faster, and can make it much worse.

Although it can't seem to happen fast enough, most cold sores will heal on their own within 10 days to 2 weeks. 

OTC treatments, like Abreva, and prescription antiviral medications can help shorten healing time.

For all the details on how to best treat a cold sore (and help manage the pain until it does) pop over to our First Aid site: How to Treat a Cold Sore.

Here's How You Can Treat a Pimple

Since pimples aren't contagious, you can't spread them to other people or to other areas of your body.

Still, that's not saying you should start messing with your zit.  Squeezing, picking, or otherwise bothering it can make the pimple much worse.  It can also cause scarring.

If you have just the one pimple, take heart knowing it should start healing within a week.  If it's super painful and swollen, you could ice it down a few times a day.

OTC acne spot treatments can also help speed healing, but only by a day or so.  Don't overuse them or they'll make your skin super dry.

And don't put any oddball things like toothpaste, Windex, or garlic on your pimple.  It won't heal it but could make it more irritated.

If you tend to get pimples a lot, or you have them over your entire face or on your body, it's time for a dedicated acne treatment.  Effective acne treatments will stop pimples before they form, so using them long-term means your skin will eventually be pimple free!

This article will help get you started on the right acne treatment: The Most Effective Acne Treatment Options.

Questions? See your Physician

Not quite sure exactly what is happening on your skin?  Is the lesion getting worse?  Call your doctor; they're there to help after all.

Your doctor can tell you if you have a cold sore, pimple, or something entirely different, with a simple exam.  Even better, your doctor can help you treat the bugger so you'll be well on your way to healing.


Ramdass P, Mullick S, Farber HF.  "Viral Skin Diseases." Prim Care. 2015 Dec;42(4):517-67.

United States. NIAMS. "Questions and Answers About Acne." Bethesda, MD: National Institutes of Health, 2006.

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