Rotten ear root, may be skin eczema, contact dermatitis, atopic rhinitis and so on. 1. Skin eczema: localized skin eczema caused by internal and external stimulation of various factors, the acute stage may cause localized skin erosion, oozing, rash, itching and other symptoms, so it is manifested as rotting ear root. 2. Contact dermatitis: for example, contact dermatitis caused by contact with allergenic substances, the use of drugs caused by drug rash and other allergic factors, may also lead to rotting ears. 3. Atopic dermatitis: a chronic inflammatory skin disease associated with genetic allergic qualities, manifested as itching, polymorphic lesions and tendency to exudate, often accompanied by asthma, allergic rhinitis, which occurs at the root of the ear can be the phenomenon of skin erosion. Rotten ear root may have other reasons, it is recommended to go to the hospital to check the cause of the disease, targeted treatment.