Back dry skin itching consider and excessive dry skin, contact dermatitis, psoriasis, neurodermatitis and so on. 1. Excessive skin dryness: when the body lacks moisture and the living environment is excessively dry, some patients will experience back dryness and itching. 2. Contact dermatitis: the disease is mainly caused by contact with exogenous substances that irritate the skin or induce allergic reactions. Patients will have localized skin erythema, swelling, pimples, blisters, etc., can also be manifested as dry itchy skin on the back. 3. Psoriasis: the cause of the disease is still unclear, may be genetic factors, environmental factors together. Patients with psoriasis have red plaques, itchy skin, dry skin rupture, silver-white scales covering the skin surface, etc. Symptoms usually involve the whole body skin, joints, and so on. 4. Neurodermatitis: Neurodermatitis can also cause dry and itchy skin on the back of some patients. At present, the cause of neurodermatitis is not clear, mainly with scratching, clothing friction, mental stress, sun exposure, etc., the patient may also appear pimples, skin thickening, hyperpigmentation and other symptoms. It is recommended that the back of the dry skin itchy people to medical examination, clear cause of the treatment as prescribed by the doctor, do not self-medication or prescription, so as not to aggravate the condition.