Hello, I can understand your concern for hyper-pigmentation and skin darkening. After analyzing your query I can get that you have the problem since a quiet long time. It can be related to simple Post inflammatory hyper-pigmentation or also know as PIH or could also be due to some genetical condition. In all of these conditions the color giving cells are over active and are produce more color to the skin. The resulting situation is manifested as slightly increased pigmentation over the affected area. I generally give a latest treatment with kojic acid, licorice extract, niacinamide or if required the azelaic acid based creams and other latest ingredient in the treatment. You can take further guidance from a dermatologist. All the best.