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.

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.

Inclusion Criteria:

• New patients with diagnosis of pemphigus vulgaris

Exclusion Criteria:

• Diagnosis of pemphigus different from vulgaris type
• Current use of adjuvant treatment other than azathioprine. A wash out period of at least 2 weeks is required before inclusion is acceptable.
• Presence of contra-indications for the use of high dose steroids
• No availability for follow-up.
• Concomitant diseases treated with oral steroids.
• Glucocorticoids administered for pemphigus vulgaris longer than two months.
• Presence of contra-indications for the use of azathioprine.