Is It a Pimple or a Cold Sore?

How To Tell the Difference and Treat Each of These Pesky Red Bumps

When you wake up with a sore, red bump next to your lip you may be wondering if it's a cold sore or a pimple. Even though these are completely different skin problems, they can start off looking very similar. How do you know the difference? Let's look at the clues that can help you distinguish the two and how to treat each.

How to Spot a Cold Sore

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

Cold sores will typically appear around your mouth or chin and between your mouth and nose. They may also form directly on your lip.

In the days or hours before a cold sore appears, you may notice that your skin itches or tingles. As it grows, a cold sore can become painful and might even throb or burn.

The First Signs of a Pimple

You might feel a pimple before you actually see it. An area just under the skin may be tender or you might feel a small lump under the skin.

Quite often, however, pimples appear without any warning. You can go to sleep one night and wake up with a big zit.  

Pimples can happen anywhere on your 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.

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

Cold Sores Are Clusters of Blisters

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.

Eventually, the blisters burst and can ooze fluid. As it tries to heal, the cold sore will scab over, crack, and ooze. 

Pimples Develop a White Head

Instead of blisters, pimples develop a white head. This is a white "peak" in the middle of the red bump. It is distinctly not a blister.

Most pimples have a single white head, but some zits get so big that they develop several heads. 

A Cold Sore Is Caused by a Virus

Pimples and cold sores develop differently as well. Cold sores are caused by a virus, specifically the herpes simplex 1 (HSV-1).

This is a very common virus. It's estimated that 50 to 80 percent of people have it, although it doesn't always cause breakouts.

HSV-1 is contagious and is spread from one person to another. You can get it from kissing someone who has a cold sore or sharing utensils and containers while eating and drinking.

A Pimple Is Caused by Bacteria

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

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

How to Treat a Cold Sore

Treating a cold sore requires patience. It will heal over time and it's important to ensure the virus doesn't continue to spread.

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 to other people or other areas of your own body.

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

Although it doesn't seem to happen fast enough, most cold sores will heal on their own within 10 days to 2 weeks. Over-the-counter (OTC) treatments like Abreva and prescription antiviral medications can help shorten the healing time.

Lip balms you apply with your finger will keep it moist and help the healing. Wash your hands before touching the balm again or you can contaminate that and prolong the problem.

How to Treat and Prevent Pimples

Since pimples aren't contagious, you can't spread them to other people or to other areas of your body. That doesn't mean you should start messing with your zit. 

Squeezing, picking, or otherwise bothering it can make a pimple much worse. It can also cause scarring.

If you have just the one pimple, take heart in knowing that it should start healing within a week. If it's very painful and swollen, consider icing it down a few times a day.

OTC acne spot treatments can also help speed healing, but only by a day or so. Try not to overuse them as they can dry out your skin.

Also, avoid all the odd things that are supposed to be "miracle" acne cures. This includes toothpaste, Windex, and garlic because they won't heal it and may actually irritate it more.

If you tend to get pimples often or have them over your entire face or body, it's time for a dedicated acne treatment. Effective acne treatments will stop pimples before they form. Many people find that using these long-term eventually takes care of the pimple problem completely.

Questions? See Your Physician

Not quite sure exactly what is happening on your skin? Is the lesion getting worse? Call your doctor.

With a simple exam, your doctor can tell you whether you have a cold sore, pimple, or something entirely different. Even better, your doctor can help you treat that pesky thing so you'll be well on your way to healing.

View Article Sources
  • Ramdass P, Mullick S, Farber HF.  Viral Skin Diseases. Primary Care: Clinics in Office Practice. 2015 Dec;42(4):517-67.
  • National Institute of Arthritis and Musculoskeletal and Skin Diseases. Questions and Answers About Acne. National Institutes of Health. 2016.