What Causes Pigmentation And Dark Patches Around Mouth?

Hi my esnophil reading is 10(high) but I don t have any cough. I do feel as if between the the nose and the mouth opening there is some phlem in the mornings. Of late the skin on my face is highly pigmented and dark patches near my mouth have developed. My LDL cholesterol is a little high. What should be my course of action?