Pemphigus encompasses a group of life-threatening autoimmune bullous diseases characterized by flaccid blisters and erosions of the mucous membranes and skin. The severity of the disease is based on its progressive course which is accompanied by an increased body catabolism with loss of body fluids and proteins and secondary bacterial and viral infections which may lead to sepsis and cardiac failure. Before the advent of systemic corticosteroids, the prognosis of pemphigus was almost fatal within two years after making the diagnosis.
Pathophysiologically, the underlying intraepithelial blister formation is caused by IgG autoantibodies against the desmosomal adhesion proteins, desmoglein and/or desmoglein 1, on epidermal keratinocytes. Pemphigus is rare and its incidence has been estimated to about 2 new patients per 1 million inhabitants per year in Central Europe. Two main clinical variants are known, pemphigus vulgaris (PV) and pemphigus foliaceus (PF). The pathogenic role of anti-desmoglein 1/3 IgG has been clearly established since the injection of patients' sera or affinity-purified IgG from pemphigus sera into neonatal mice reproduces immune pathologically and clinically the cardinal symptoms of pemphiguswithin 24 hours. In most patients, disease activity is closely correlated with serum levels of desmogleinreactive autoantibodies. Due to its rarity, only few prospective controlled clinical trials are available in pemphigus which are limited by the low numbers of patients studied and the lack of statistically significant differences in many studies. A few studies compared different doses of prednisolone, i.v. corticosteroid pulses versus placebo, azathioprine versus mycophenolate mofetil, and the use of adjuvant treatment with methotrexate, cyclosporine, cyclosphosphamide, and high-dose intravenous immunoglobulins. The combination of systemic corticosteroids (prednisolone, 1.0-1.5 mg/kg/d) and corticosteroid-sparing immunosuppressive drugs, mostly azathioprine and mycophenolate mofetil, is regarded as standard first-line therapy by most dermatologists.
However, no internationally accepted treatment guidelines exist despite efforts to provide national guidelines in several European countries such as in France and United Kingdom. For this reason, a group of European dermatologists with a longstanding interest and expertise in basic and clinical pemphigus research has sought to define diagnostic and therapeutic guidelines for the management of patients with pemphigus.