Scleroderma--demographics and survival.

Scleroderma is a rare disease with limited data on its occurrence. Published prevalence rates vary widely with contemporary studies based on hospital ascertained cases, reporting rates of 30-120/million population. The annual incidence of new cases is much lower with rates of 2-20/million/year. Rates are substantially higher in females with a peak onset in the fifth and sixth decade. The disease is associated with a substantially reduced survival with approximately 50% surviving 10 years. Again, there is wide variation among studies probably reflecting patient selection factors. Apart from an increased risk of death from scleroderma related causes, there is also an increased cancer mortality particularly of the lung.