What can I do to lighten up knees and toes?

Thanks for your query. There are multiple options available for lightening up the knees and elbows. You can go in for microdermabrasion along with chemical peels as they will exfoliate it deeply and lighten up the skin. It can take up to many sessions for the result. Minimum of 6 peels may be required for the lightening of skin. Hope it helps.vAll The Best