Pigmentation and itching on one side of the vulva is considered to be related to local friction, vulvar folliculitis and vulvar eczema. 1. Local friction: if the patient is obese, it will cause the friction between the vulva and the inner thighs local tissues, which will cause local hyperpigmentation, itching and other discomforts. 2. Vulvar folliculitis: because the vulva has the distribution of urethral opening, vaginal opening and anus, so when the body resistance is low, it is easy to cause a large number of bacterial reproduction and cause vulvar folliculitis, and it is easy to leave pigmentation after scratching. 3. Vulvar eczema: If there are symmetrically distributed papules and blister-like rashes, accompanied by obvious itching, we should be alert to the occurrence of eczema. Due to the stimulation of local inflammatory exudate, it is easy to develop hyperpigmentation and thickening of the skin in the long run. For patients with hyperpigmentation and itching on one side of the vulva, it is recommended that they go to the gynecology or dermatology department of a regular hospital, and be treated under the guidance of the doctor after clarifying the cause of the disease.