Cold sores are fluid-filled red blisters on the lips and skin
around them. They can also appear in and around the nose
and on the cheeks.
Some people do not find cold sores painful. They just notice
a tingle or an itch. Others find them painful, especially when
they break open. This is called “weeping” because the fluid inside leaks out.
Cold sores last 7 to 12 days. Blisters form, then break open and ooze. Finally, a
yellow, crusty scab forms.