Share This Post

Is This a Cold Sore or Something Else?

Written by Katherine Gonzalez, FNP-BC, IBCLC

Look-a-likes can include angular cheilitis, impetigo, and eczema, oh my!

Cold sores 101

Cold sores are caused by the herpes virus, and causes painful, fluid filled blisters. Over the course of a week or so the blisters typically open up and drain, then crust, scab, and heal. Cold sores usually occur near the lips, but can also occur on other skin areas. Usually they will heal on their own without scarring, but the healing time may take a couple of weeks.

Could my mouth sores be something else?

There are other medical conditions that can cause cold sore-mimicking symptoms. Typically the medications used to treat cold sores won’t make other types of mouth sores go away, so it’s especially important to talk to your doctor if your cold sore isn’t healing.

Angular Cheilitis

If your sores are located in the corners of your mouth, it might be angular cheilitis. These sores can be caused by bacteria or fungal organisms. Treatment is usually a cream, but this condition needs to be diagnosed in person typically.

Canker sores

Canker sores, also known as aphthous ulcers, are painful sores that happen inside the mouth, on the tongue or gums, and typically look white or yellow. These are not caused by an infection. In some people they come on due to stress or trauma in the area (such as biting your lip or tongue). Cold sores typically happen outside of the mouth, but in some people, a cold sore outbreak can trigger a canker sore as well.


Impetigo is the name for a bacterial infection that causes fluid filled blisters. These can occur around the nose and mouth and often look yellow (or honey- colored) after they burst. Treatment is antibiotics, either taken by mouth or applied directly to the sores. Sometimes impetigo can happen on top of a cold sore, so it’s important that your doctor takes a close look at the sores.


If you suffer from eczema, you can develop it around your mouth as well. Eczema near the lips can cause a painful, red rash that sometimes itches. Treatment includes steroids and it won’t get better if you’re on treatment for cold sores.


Rosacea is a chronic condition that causes redness and sometimes pus-filled blisters on the face, sometimes around the lips. Treatment includes antibiotics and other topical creams, rather than the medicines used for cold sores.

Perioral dermatitis

This bothersome skin condition is kind of a cross between acne, rosacea, and eczema. It tends to happen on the skin around the mouth and may look like bumps, acne, or a red rash. Putting hydrocortisone or other topical steroids on it tends to make it worse and it’s best treated by a dermatologist. Cold sore medications typically will have no effect on this condition.

The views expressed in this article intend to highlight alternative studies and induce conversation. They are the views of the author and do not necessarily represent the views of HeyDoctor, and are for informational purposes only, even if and to the extent that this article features the advice of physicians and medical practitioners. This article is not, nor is it intended to be, a substitute for professional medical advice, diagnosis, or treatment, and should never be relied upon for specific medical advice.

Check out the HeyDoctor app

With over 1,000 5-star reviews, we're one of the highest rated medical apps. See for yourself!