Thanks for the query. It all depends the etiology causing the dark spots. If the disease has burnt out totally leaving these so called post inflammatory pigmentation, various treatment options can be attempted.Targeting through a single agent may not always be fruitful. Meet a qualified Dermatologist to learn more about the diagnosis and treatment options. Combination of different therapeutic agents is always beneficial. Revlite I.e. Q Switched Nd YAG laser can also be available. Certain depigmenting agent can also be tried. Hope it helps. Dr MK Agarwala  Dermatologist