The skin something like the elbows and knees is typically thicker and has more folds than its nearby skin. Also, because there are no lubricate glands in these part, this skin tends to be drier. So, when correct care and hygiene is not maintain, the skin on knees plus elbows becomes a lot darker than additional parts of your body.
Other factors like recurrent rubbing, over-exposure to the sun, inherited factors, dry skin, hormonal inequity, obesity, dull skin buildup and more are causes of mysterious elbows and knees but there are home remedies to contract with them. Hope you like this remedy.