The causes of itchy hands and feet include herpes sweat, tinea cruris, eczema on hands and feet, contact dermatitis and so on. 1. Sweat herpes: in case of sweat herpes, at this time, due to the sweaty skin, the sweat accumulates in the skin to trigger the inflammation of the skin, which results in itchy rashes. 2. Ringworm: In the case of ringworm, this is due to fungal infections of the hands and feet, and these fungi are able to invade the skin, leading to skin damage and itchy symptoms. 3. Eczema of the hands and feet: in case of eczema, due to a variety of factors triggering an inflammatory reaction of the skin, various rashes appear on the skin, accompanied by itching. 4. Contact dermatitis: When the skin comes into contact with certain stimulating or sensitizing substances, the large amount of histamine produced triggers swelling of the skin and itching. Finally, serious itchy hands and feet phenomenon, please go to the hospital in time to check, after a clear diagnosis under the guidance of the physician to give systematic treatment.