Spectrum of subepidermal immunobullous disorders seen at the National Skin Centre, Singapore: a 2-year review

Abstract

The subepidermal immunobullous disorders (SEIBDs) comprise bullous pemphigoid (BP), cicatricial pemphigoid (CP), epidermolysis bullosa acquisita (EBA), linear IgA disease (LAD), dermatitis herpetiformis (DH), pemphigoid gestationis (PG) and bullous systemic lupus erythematosus (BSLE). They are thought to be rarer in the Far East than in western Europe. This 2-year retrospective study investigates the spectrum seen at our centre and the minimum estimated incidence of each. A total of 67 patients seen at the National Skin Centre (NSC), Singapore between January 1998 and December 1999 were diagnosed as having an SEIBD. Fifty-nine (88%) had BP, four (6%) had EBA, two (3%) LAD and two (3%) BSLE. There were no cases of CP, DH or PG diagnosed during this period. The minimum estimated incidence in our local population was 7.6, 0.5, 0.26 and 0.26 per million population per year, respectively. The mean age of onset was 77, 68, 65 and 31 years, respectively. BP is the commonest SEIBD seen locally, with an incidence at least equal to that in western Europe. It is diagnosed at our centre three times more frequently than pemphigus. There is a predilection for ethnic Chinese but not Indian. EBA is twice as common as in western Europe and shows a predilection for ethnic Indians. LAD is rare here compared to China, despite the predominant Chinese population. BSLE is also rare. In contrast to western Europe, CP, DH and PG are very rare in Singapore. This is the first study from this region to show that certain SEIBDs are not rarer in the Far East, as previously thought.