Patchy baldness usually stops spreading hair loss after 3 to 4 months. Pemphigus vulgaris is a psychogenic, autoimmune-related, non-scarring hair loss disease. According to the stage of the disease, it can be categorized into progressive stage, stationary stage, and recovery stage. In the progressive stage, the hair at the edge of the alopecia areata appears loose and easy to pull out. And under the microscope can be seen in the proximal atrophy of the hair, stationary phase, hair loss area edge hair is no longer loose, generally 3 ~ 4 months into the recovery period. So baldness, 3~4 months later can stop spreading hair loss. Into the recovery period there will be new hair growth, the beginning of the performance for the fine soft light-colored vellus hair, gradually thickening, the color will become darker, and finally return to normal hair. It is recommended to consult a doctor in time and take appropriate treatment measures under the doctor’s guidance if symptoms of spot baldness appear.