The itchy skin on the left chest of a man may be caused by urticaria, eczema, ringworm, etc. Patients can take oral or topical medication to improve the condition after clarifying the specific cause of the disease under the guidance of a doctor. 1. Urticaria: Urticaria is usually caused by increased permeability of blood vessels due to allergic factors. In the treatment, you can take oral antihistamines to relieve itching, such as levocetirizine hydrochloride, olopatadine hydrochloride and so on, and you can use topical glycerine lotion. 2. Eczema: Eczema is usually caused by repeated contact with allergic substances or allergic foods. Topical glucocorticosteroid drugs, such as Denadyl cream, hydrocortisone butyrate cream, etc., can be used in the treatment. 3. Tinea corporis: Tinea corporis refers to the skin ringworm infection that occurs in the superficial parts of the skin; it can be treated with topical antifungal drugs such as naftifine ketoconazole cream. Caused by male patients left chest skin itchy reasons, it is recommended to timely to the regular hospital for examination, under the guidance of a professional doctor symptomatic treatment, not blindly use their own medication.