Cold sores are small, fluid-filled blisters that typically form in clusters on or around your lips. They start as a tingling patch of skin, develop into red, raised blisters filled with clear fluid, and eventually crust over into a yellowish-brown scab before healing completely. The whole process takes 7 to 10 days without treatment.
What Cold Sores Look Like at Each Stage
Cold sores change appearance significantly as they progress through five distinct stages, so what you see depends on when you catch it.
In the first stage, there’s nothing visible at all. You’ll feel tingling, burning, or itching in a specific spot, usually along the lip line, but the skin still looks normal. This lasts roughly a day.
By stage two, one or more small blisters filled with clear fluid appear on the surface of the skin. The skin around and underneath them turns red. These tiny blisters often group together in patches and may merge into a larger blister. This cluster pattern is one of the most recognizable features of a cold sore.
Within a few days, the blisters break open. This is the weeping stage, and the sores look red and shallow, almost like a small raw wound. Clear or slightly yellow fluid oozes from them. This is also when cold sores are most contagious.
As the open sore dries out, it forms a crust that looks yellow or brown. This scab can crack and bleed, which is normal but uncomfortable. Finally, the scab flakes away gradually over the last few days, leaving behind skin that may look slightly pink for a short time before returning to normal.
Where They Appear on Your Face
Cold sores most commonly form along the border of the lips, right where the colored part of the lip meets the surrounding skin. But they can also show up on the skin around the mouth, on the nose, and on the chin. One distinctive trait is that cold sores tend to recur in the same spot each time you get an outbreak, so if you’ve had one before, the next one will likely appear in a familiar location.
Cold Sores vs. Pimples
A pimple on your lip forms a single raised red bump, often with a whitehead or blackhead at its center. A cold sore, by contrast, is a cluster of fluid-filled blisters that ooze and eventually scab over. Pimples don’t go through that progression of blistering, weeping, and crusting.
The sensation is different too. A lip pimple hurts the way any pimple does, with pressure and tenderness. Cold sores produce a distinctive tingling and burning feeling, often before anything is even visible on the skin. If you felt a buzzing or itching sensation a day before the bump appeared, that points strongly toward a cold sore.
Cold Sores vs. Canker Sores
The simplest way to tell these apart is location. Cold sores form on the outside of your mouth, around the lips and surrounding skin. Canker sores only appear inside the mouth, on the inner cheeks, inner lips, or tongue.
They also look quite different up close. Cold sores are patches of several small fluid-filled blisters. Canker sores are single, round sores that are white or yellow in the center with a red border. Canker sores are not caused by the herpes virus and are not contagious.
Signs of a Bacterial Infection
Cold sores can sometimes pick up a secondary bacterial infection, and knowing what that looks like helps you catch it early. A normal cold sore crust is yellowish-brown. If the crusting turns distinctly honey-colored, spreads beyond the original sore, or the surrounding skin becomes increasingly red and warm, a bacterial infection called impetigo may have developed on top of the cold sore. Impetigo produces sores that rupture and form thick, golden crusts, and it can spread to other areas of the face, particularly around the nose.
When Cold Sores Affect the Eyes
In rare cases, the herpes virus can spread to the eye area. This can cause redness and irritation in the eye itself, blisters or a rash on the skin around the eye, watery discharge, swelling, or a drooping eyelid. These symptoms typically affect only one side of the face. If you notice blistering near your eye during or after a cold sore outbreak, that warrants prompt medical attention, since untreated eye herpes can affect vision.