The itchiness in the middle of the two chests may be caused by physiological reasons, chest eczema, mosquito bites, herpes zoster and so on. 1. Physiological reasons: If the environment is relatively humid, hot, it will easily lead to sweating, so that the sweat stimulates the middle of the chest local skin, the middle of the two chest skin itchy situation, which is a normal physiological phenomenon. 2. Chest eczema: If the skin in the middle of the two chests comes into contact with certain allergic or irritating substances, such as chemical fiber clothing, shower gel, etc., it will easily cause an allergic reaction to the chest and the surrounding skin, triggering eczema, resulting in itchy skin in the middle of the two chests. 3. Mosquito bites: If the skin in the middle of the chest is bitten by mosquitoes, insect bite dermatitis will easily occur, resulting in red rashes in the middle of the chest and itchy symptoms. 4. Herpes zoster: when the skin in the middle of the chest is infected with chickenpox-herpes zoster virus, it will cause herpes zoster, resulting in a red rash in the middle of the two chests and itchy symptoms. After excluding physiological causes, patients with itching in the middle of the two chests should go to the hospital in time, and actively cooperate with the doctor after clarifying the cause of the disease.