The redness and itching on the back of the hands may be related to allergy, ringworm and frostbite, etc., and the specific conditions need to be examined by a doctor to confirm the diagnosis. 1. allergy: when the allergen through the skin mucous membrane into the body can lead to the body produce abnormal immune response, so that the back of the hand redness, itching symptoms, but also can be accompanied by tingling, redness and swelling and other clinical symptoms. 2. ringworm: when the dermatophytes invade the skin of the back of the hand can cause fungal infection, so as to appear. 2. ringworm: when the dermatophytes invade the skin on the back of the hands can cause fungal infection, thus appearing on the back of the hand erosion, itching symptoms, but also can be accompanied by dandruff, blisters, cracks and other clinical manifestations. Close contact with people suffering from tinea cruris may lead to infection. 3. frostbite: refers to the local or systemic injury caused by low-temperature cold attack on the body, hand frostbite can be manifested as abnormal hand sensation, skin changes. Specifically manifested in the hands can have cold feeling and pinprick pain, accompanied by burning itch, numbness. The skin of the hand is pale, and localized erythema, cyanosis and edema can be manifested. If you find that the back of the hand is red and itchy, you should consult a doctor in a timely manner, and follow the doctor’s instructions for treatment after a clear diagnosis, and do not take any action without authorization, so as not to delay the condition. Pay attention to skin care on weekdays, avoid contact with allergens, and maintain personal hygiene.