Hello! Any new dark patches on the lips or skin should be examined by a dermatologist to determine if it is suspicious and requires further testing.
A common cause of lower lip pigmentation would be a harmless condition known as labial melanotic macule.
This is essentially a harmless freckle affecting the lip. Occasionally, these can be associated with other serious syndromes so a quick consultation is advised.
These pigmented patches are easily removed using a pigment laser. It often lightens rapidly after just 1-2 treatments. Hope this helps!
Warm regards
Dr Stephanie Ho, Dermatologist
