Hey I would love to have an answer as soon as possible. My brithday is next Friday and I wanted to wear a dress but I can't because of this problem. Thank you for taking your time to read this!:D

Knees and elbows can be rough and dry, causing the skin in these areas to appear darker. You should use a good moisturizer every day to soften your knees and elbows. You can also use a skin lightening cream that contains hydroquinone to help lighten the dark discoloration. If these measures don't work, see a dermatologist for a treatment that's right for you.