It is likely to be caused by immune deficiency and autoimmune system disorders. It is a hemispherical blister with white and yellow turbid pus, several centimeters in diameter, up to 7 centimeters in size, with clear borders, surrounded by a red halo and no pain, which breaks down to form a vesicle and easily causes infection. The main treatment is to prevent the pustules from exuding and invading the surrounding tissues and spreading the area, and to deal with the skin damage according to the dermatology topical medicine to reduce the symptoms, promote healing, and prevent secondary infections, with appropriate oral hormones, a little topical halomethasone cream, and anti-inflammatory and pain relief cream for symptomatic treatment.