As soon as the sweat face itchy, if due to allergic reaction, light can be cleaned first, heavy can be oral anti-allergy drug treatment; if due to eczema, can be used externally ointment treatment. 1. Allergic reaction: If the face itches when you sweat, it may be related to the skin contact with external substances allergies, sweat aggravates the allergic reaction. If the symptoms are mild, you can first use water to wash the sweat to see if there is relief; if there has been no relief or itching is serious, you can take anti-allergy drugs, such as loratadine to treat. 2. Eczema: Eczema is an inflammatory skin disease, also occurs in the face skin, can also appear as soon as the sweat on the itchy situation, usually by applying glycerine lotion to stop itching, if the effect is not good, you can also use dexamethasone cream to treat. Therefore, when the face itches when sweating, you can usually wash the sweat first, if it has not been relieved, it is recommended to consult a doctor to identify the cause, and then under the guidance of the doctor for treatment.