how to lighten dark knees and elbows: Safe Protocols for Dark Knuckles, Knees, and Namaz MarksQuick Summary:Friction hyperpigmentation on elbows, knees, ankles, and prayer marks is caused by repeated mechanical pressure stimulating melanocytes in thicker epidermal layers. Fading it safely on South Asian skin requires a non-bleaching routine: tyrosinase inhibitors...