Comparison of patients with and without digital ulcers in systemic sclerosis: detection of possible risk factors

Background Digital ulcers (DU) are a major complication in the course of systemic sclerosis (SSc). In recent years, efficacious, but expensive therapies (e. g. iloprost, sildenafil, bosentan) have been shown to improve healing or to reduce the recurrence of DU. For optimal management it would be useful to identify the risk factors for DU. Such statistical analyses have been rare because they require a high number of patients. Objectives To identify potential risk factors for DU in patients with SSc. Methods We used the registry of the German Network for Systemic Scleroderma and evaluated the data of 1881 patients included by August 2007. We assessed potential risk factors for DU by comparing patients with (24.1%) and without active DU at time of entry (75.9%). Results Multivariate analysis revealed that male sex, presence of pulmonary arterial hypertension (PAH), involvement of the oesophagus, diffuse skin sclerosis (only when PAH was present), anti-Scl70 antibodies, young age at onset of Raynaud's phenomenon (RP), and elevated erythrocyte sedimentation rate (ESR) significantly impacted on the appearance of DU. Certain combinations increased the patients' probability of presenting with DU, with the highest probability (88%) for male patients with early onset of RP, ESR > 30 mm h(-1), anti-Scl70 antibodies and PAH. Patients with DU developed RP, skin sclerosis and organ involvement approximately 2-3 years earlier than patients without DU. Conclusions The results reveal possible risk factors for the occurrence of DU in SSc. As DU are prone to local complications, prophylactic vasoactive treatment for patients presenting with these factors may be justified.