Background: Systemic rheumatoid vasculitis (SRV) is a relatively rare complication of RA. The incidence of SRV appeared to increase during the 1970s and 1980s from 6.0 to 12.5/million. During the 1990s there have been major changes in the treatment of RA, with more aggressive control of inflammation. Our aim was to study the epidemiology of SRV in a stable, well-defined population over a 15-yr period.
Methods: Since 1988 we have maintained a prospective register of all patients with systemic vasculitis attending the Norfolk and Norwich University Hospital. Patients presenting with new-onset SRV, as defined by the criteria of Scott and Bacon, and registered with general practitioners in the former Norwich Health Authority area between 1988 and 2002 were identified. The population in 2002 was estimated to be 445 000 (215 000 males).
Results: Fifty-one patients (24 male) with SRV were identified, with median age 61 yr and disease duration 16.8 yr. The overall annual incidence was 7.9/million (95% CI 5.9-10.4) (males, 7.7/million; females, 8.1/million). During the first quinquennium (1988-92) the incidence was 11.6/million (95% CI 7.4-17.0) and during the third (1998-2002) it was 3.6/million (95% CI 1.6-7.1). A rolling 3-yr average showed that the peak incidence was in 1992-94, at 15.2/million (95% CI 9.1-23.8), and the nadir was in 1998-2000, at 3.0/million (95% CI 0.8-7.8). A similar pattern was seen for males and females. There was no difference in age or disease duration at onset of SRV between the three quinquennia.
Conclusions: The incidence of SRV has declined dramatically since the 1980s. This could be due to better control of inflammatory disease or changes in smoking habits.