This is tinea pedis, a fungal infection, or beriberi! It is suggested to use traditional Chinese medicine, such as Zuguang powder, as a medicinal bath. Super cool after soaking, even if you sweat, it won't stick to your feet. A layer of skin will fall off in a few days, and the new skin will grow very slippery. Then take medicine to remove this ointment, put it on, and stick to it every day. No side effects, just to prevent fungal infection.