To establish the clinical significance of isolated nail fold vasculitis in patients with rheumatoid arthritis (RA).
Patients attending hospital with established RA were assessed by a single observer using unaided vision. Isolated nail fold vasculitis (NFV) was diagnosed as small nail edge or nail fold lesions without any evidence of other extra-articular or systemic vasculitis. Patients were followed prospectively.
Thirty patients with isolated NFV were identified and followed for a median interval of 22 months. Three patients died within three months of diagnosis and six developed complications possibly indicative of extra-articular disease: xerostomia (three), pericarditis (one), pleural effusion and empyaema (one), pulmonary fibrosis (one). No patient developed systemic vasculitis.
Isolated NFV has a favourable prognosis compared with systemic vasculitis. There is a low risk of developing systemic or extra-articular disease.