Mostly due to external wind, dampness, heat of the poison, accumulation of skin; disease for a long time, the blood can not be Rongrun, the skin loss of nourishment, so that the skin is fat and dry, shaped like a goose's paw; or by mutual contact, the poisonous evil infected, can be infected with other people; can also be infected with foot infected and get.

Western medicine believes that this disease is due to the growth of the palms of the hands and between the fingers of the skin infection caused by fungi, mainly red ringworm, trichophyton and flocculent epidermal fungi.