Systemic sclerosis in Iceland. A nationwide epidemiological study.

OBJECTIVES: To investigate the incidence, prevalence and clinical features of systemic sclerosis (SS) in Iceland. METHODS: All patients diagnosed with SS from 1975-90 were included. Retrieval for the study began in 1980 and was carried out by computerised search from registers of all hospitals and health care clinics and death registration files, and with personal communication with doctors in Iceland. RESULTS: Over a 16 year period from 1975-90, 15 new cases were found with an incidence of 0.7 and 0.05/100,000, for females and males at risk respectively, and 0.38 for both sexes. At the end of 1990 there were 18 patients alive with SS, 13 with limited and five with diffuse cutaneous involvement. The age standardised prevalence was 11.9 and 1.5/100,000 for females and males at risk respectively. The crude prevalence rate for both sexes was 7.1/100,000. There were five deaths, two patients died of SS related causes, one had SS renal disease. The relative risk of death was similar to that in the general population. The calculated five year survival rate was 100% and the 10 year survival rate 81%. No HLA antigen association was found. CONCLUSION: Compared with previous surveys this study shows a low incidence of systemic sclerosis and a high proportion of patients with limited cutaneous involvement.