Hello, Welcome to healthcare magic. Post inflammatory pigmentation is a term used for pigmentation which arises secondary to an injury/ inflammation to the skin like trauma, acne, burns, etc. You have not mentioned how your acquired this pigmentation. Depending on the extent of initial inflammation, the pigmentation can be superficial or deep. Superficial pigmentation responds faster and well to lightening creams like kojic acid. Deep pigmentation may not completely disappear. Continue to use the creams and sunscreen that you are currently using. You could opt for chemical peels done by a dermatologist. Peels containing glycolic acid and retinol hep in lightening. You could also consider Q-switched Nd-Yag laser. But the benefit of the laser depends on the type of pigmentation. Hence it needs to be evaluated by a dermatologist. Hope this helps you. Take care.