The first thing to determine if there are large red spots, swelling, blisters, or even itching symptoms on the back of the feet. If there are similar symptoms, they may be caused by mosquito bites and the patient should avoid scratching. If it inadvertently breaks down, leading to infection and other situations, you need to seek medical help at the hospital. In addition, there may be the following diseases: 1, allergic reactions: such as the dorsum of the foot due to contact with animal hair, wearing chemical fiber composition socks, etc., allergic to produce red papules, and accompanied by a more pronounced itching sensation, may be an allergic reaction, should avoid contact with allergens, if necessary, under the guidance of a doctor for drug and desensitization treatment; 2, tendon sheath cysts: the back of the foot around the tendon sheath due to long-term and tendon friction and mucus appears. The tendon sheath cysts, which occur in young adults, especially in women who often wear high heels, diabetic patients and cargo handlers, can be diagnosed differently by ultrasound; 3, sebaceous cysts: sebaceous glands secrete sweat, which cannot be discharged due to sebaceous duct obstruction and long-term accumulation will lead to the formation of bulging skin, i.e. sebaceous cysts. The sebaceous glands open small holes, usually round, medium hardness or elasticity, no fluctuation, smooth surface, clear border, small volume, the center often has a needle point size depression, press the periphery can overflow white contents, secondary to bacterial infection, local redness, pus and pain symptoms; 4, lipoma: fat accumulation to form a bulge, the surface is smooth, with good mobility, pushing the base of the tumor can make The skin may appear “orange peel-like” texture without obvious pressure and pain. If it presses on the peripheral nerves, it may cause pain and numbness. The gold standard for the diagnosis of lipoma is to remove the tumor by puncture or surgery and then take the tissue for pathological examination. The growth on the back of the foot is not limited to the above cases. If pain, redness and swelling occur, you should actively go to the hospital for diagnosis and treatment. There is no special medicine for the above cases, and surgical excision treatment is required. After surgical treatment in a regular hospital, one should try to keep a light diet and pay attention to rest to avoid recurrence.