Hi Amila, Welcome to HealthcareMagic Forum.
Burn marks do go with time on their own. Kindly get yourself examined by a Dermatologist
, he shall examine you and Prescribe medications. Most of the Medications use various combinations of sunprotective or antimelanocytic solutions. They can make the marks lighter. Don't use them on acute wounds or if they irritate the skin.
Wish you Good Health, Take Care.