Pemphigus is a severe chronic dermatological disease which appears to be incurable. Oral glucocorticoid now forms the cornerstone of treatment. From previous uncontrolled studies it has been suggested, that the use of high dose intravenous glucocorticoid pulse therapy may lead to complete remission without further therapy. Prospective placebo-controlled studies of adjuvant pulse therapy for pemphigus are lacking. This prospective, multi-centre, randomised, double-blind, placebo-controlled trial assesses the efficacy and steroid-sparing effect of oral high-dose glucocorticoid pulse therapy as adjuvant added to the standard combination therapy of prednisone and azathioprine in the treatment of pemphigus vulgaris, in terms of complete remission rate (primary endpoint), initial control, disease control, and adverse events. In the experimental arm glucocorticoid pulse therapy is given, comprising monthly pulses with 300mg oral dexamethasone on three consecutive days. In addition the patients receive daily prednisone and azathioprine treatment, the latter dose adjusted to the thiopurine-methyltransferase level. In the control arm the glucocorticoid pulse therapy is replaced double blindly by monthly oral placebo capsules on three consecutive days. in addition the patients receive the same daily combination schedule with prednisone and azathioprine as in the experimental arm. This study design requires 30 patients in each arm, with one year follow-up. Only new patients with pemphigus vulgaris and/or pemphigus oris are included.