I had ring worm infction(not clinically diagnosed), and cleansed it with hydrogen peroxide. 3yrs after there is still hyperpigmentation, is it normal?

Hard to say: From your comments the only facts known are that something was there 3 years ago and you now have a heavily pigmented area.An examination of the area may or may not reveal the initial cause.An exam at the time of the original condition may have led to a more specific diagnosis and treatment.

Irritation of skin: often provokes increased pigmentation. This takes a long time to decrease and often does not totally go away. dermatologic conditions are hard to discuss without seeing them, so I cannot comment with surety.