i, The dark pigmentation near your lip area is known as Post Inflammatory Hyperpigmentation/ Post Inflammatory Hypermelanosis (PIH) due to the activity of melanocytes which are the color producing cells. It is a condition of the skin arising from over activity to the skin resulting in healing with pigmentation. If I were your dermatologist then for dark pigmentation I would have suggested you to use azelaic acid cream or Kojic acid cream or glycolic acid cream or licorice extract or arbutine creams at night time. Most importantly you should do strict sun protection. Take care.