Epidemiology and Factors Associated with Remission of Pemphigus Vulgaris and Foliaceus in Singapore

Background: Pemphigus is a chronic, relapsing immunobullous disease. There is limited data on the clinical course and prognostic factors of pemphigus in Asian patients. Methods: We conducted a retrospective cohort study of all newly diagnosed pemphigus vulgaris (PV) and pemphigus foliaceus (PF) patients seen at the National Skin Centre from 1 January 2004 to 31 December 2009. Demographic and clinical data on co-morbidities, treatment and remission were recorded. Mortality information was obtained from the National Registry of Diseases. Prognostic endpoint was overall remission at last visit. Results: Sixty- one patients (36 PV and 25 PF) were recruited. Among PV patients, higher initial prednisolone dose (P = 0.017) and the use of azathioprine (P = 0.028) were significantly associated with overall remission at last visit. However, higher desmoglein 1 antibody titres at diagnosis (P = 0.024) and the use of dapsone (P = 0.008) were negatively associated with overall remission at last visit. Among PF patients, only higher desmoglein 1 antibody titre at diagnosis (P = 0.041) was found to be associated with lower overall remission at last visit. There was no mortality during the 3-year follow-up period in both PV and PF. Conclusions: Higher initial prednisolone dose and the use of azathioprine in PV desmoglein 1 antibody titre at diagnosis in PV and PF might be prognostic markers for achieving remission. Use of dapsone was associated with lower overall remission in PV, but this might be confounded because dapsone was used as an adjuvant therapy in recalcitrant cases. Owing to study methodology and limitations, further evaluation is needed for better prognostication of pemphigus.Ann Acad Med Singapore 2020;49:367–76Key words: Autoimmune blistering disease, Dermatology, Pemphigus foliaceus, Pemphigus vulgaris, Remission