Unilateral nipple itching may be caused by breast eczema, neurodermatitis, breast eczema-like cancer and other diseases. 1. Breast eczema: this disease may be related to mental tension, heredity, breast milk stimulation, wearing tight underwear for a long time. Most of the lesions are unilateral or symmetrical, occurring in areola, nipple and other places, local itching, erythema and other symptoms, so unilateral nipple itching may be caused by breast eczema. 2. Neurodermatitis: Studies show that the causes of this disease include poor sleep, impatience and other neurological factors, as well as wearing hard clothes, woolen products caused by physical friction, as well as endocrine disorders, gastrointestinal dysfunction and other factors. Clinical symptoms are characterized by single or multiple erythematous lesions, so patients will experience unilateral nipple itching, dry skin and other symptoms. 3. Mammary eczema-like carcinoma: the etiology of this disease is still unclear, which may be related to hormone level disorders, family history of breast cancer, radioactive exposure and other reasons. Typical symptoms are itching, reddening and flaking of one side of the nipple, which may be manifested as unilateral nipple itching. At the same time, nipple itching may also be seen in skin allergies, inflammation of the mammary gland may. It is recommended that patients with unilateral nipple itching go to the hospital, complete the examination, clarify the cause of the disease and standardize the treatment under the guidance of the doctor.