Localized pruritus belongs to a kind of pruritus, which is a dermatological symptom with only itchy skin without primary skin damage. The etiology can sometimes be the same as that of generalized pruritus, which can include the following aspects: 1. Internal causes: 1. Systemic diseases: digestive system, genitourinary system, hematological diseases, autoimmune diseases, etc. can be accompanied by pruritus; 2. Malignant tumors: patients with leukemia, Hodgkin’s disease, mycosis fungoides and other lymphomas, as well as malignant tumors, can generally develop pruritus symptoms in the early stage; 3. Neuropsychiatric system disorders. People who are mentally stressed, depressed or anxious are sometimes prone to generalized or restricted pruritus, and some patients with neurological abnormalities may have hallucinations of worms in the skin and feel itchy on their own. In addition, itching can also be conditioned reflexes; 4. Endocrine disorders: diabetes mellitus, thyroid disease can often cause pruritus. Pregnant women also often pruritus or pregnancy itchy rash, after menopause female pubic itching is also related to endocrine changes; 5, infectious diseases: such as cholecystitis, dental caries, gingivitis and internal parasitic infections can trigger itching; 6, dietary drug factors: easy to allergenic irritant diet, taking certain allergenic or bile causing drugs and alcohol consumption can trigger or aggravate the itching symptoms. Second, external factors: 1, environmental factors: such as a sudden cold, or the environment is too dry, humid, hot, then the skin can cause stress itching; 2, irritating substances: excessive use of alkaline cleaning products, use or contact with kitchen degreaser, insecticides, disinfectants, and wearing chemical fiber intimate apparel, these situations may stimulate the skin, causing itching.