Hello,
From the picture and description of your symptoms,it sounds like
xanthomas. Xanthoma is a skin condition in which fat builds up under the surface of the skin.
A xanthoma looks like a sore or bump under the skin. It's usually flat, soft to the touch, and yellow in color. It has sharp, distinct edges and are most often seen on the elbows, joints, tendons, knees, hands, feet, or buttocks.