Itchy back may be caused by localized dry skin, seborrheic dermatitis, neurodermatitis and so on. 1. Localized dry skin: dry weather, excessive cleaning and other reasons can cause back dryness, which leads to itchy back. 2. Seborrheic dermatitis: it is a common chronic inflammatory skin disease that occurs in parts of the human body where sebum secretion is exuberant, such as the head, face, chest, back, etc. It mainly manifests itself in the form of itchy skin, erythema, and flaky skin flakes in the affected areas. It can also cause the back to be very itchy. 3. Neurodermatitis: also known as chronic lichen simplex, mainly manifested as paroxysmal intense itching of the affected skin and mossy skin, but also accompanied by pimples, skin pigmentation, scarring and other symptoms. If it involves the back, it can cause the back very itchy. There are many other causes of itchy back, which should be taken seriously, timely consultation, identification of the cause of the disease, and follow the medical advice for further treatment or therapy.