Pemphigus vulgaris is a common skin and mucous membrane disease with hair loss. It is divided into three phases, active phase, resting phase and recovery phase. As the name suggests, the so-called active phase is the stage in which hair loss will continue and the scope of hair loss will continue to expand, and this time is different for each patient. However, when the hair loss slowly stops, the patient will enter the quiescent phase, which means that the patient basically will not lose hair again. The so-called resting period means that the patient basically will not lose any more hair. After the resting period passes, the patient will enter the recovery period, which is about 3-4 months for the majority of patients. During the recovery period, there will be fresh hair growth on the scalp. The hairs that appear at the beginning are fine and soft, and very light in color, but these hairs will slowly become thicker, harder, darker, and gradually return to normal.