I have been using Retin a 0.05% for more than a month and recently my skins appear to have some melasma and redness like the result of sunburn although I use sunscreen every day. My skin looks so dark and the cheeks have some dark marks like hyper pigmentation. My acne has improved significantly but these side effects scare me a lot. Please help me. Will the erythema and hyperpigmentation disappear? What should I do to improve my the hyperpigmentation during the time using it? Thanks a lot.