By this study, the investigators want to test if the value of adjuvant pulse glucocorticoid therapy for pemphigus can be determined by comparing an experimental arm (dexamethasone pulse therapy, prednisolone, and azathioprine) with a control arm (placebo pulse therapy, prednisolone, and azathioprine). The investigators will determine the rate of complete remission with dexamethasone pulse therapy; the time needed for complete remission; and the duration of remission, and compare these data with those of the placebo arm.