Capillaroscopic skin ulcer risk index: a new prognostic tool for digital skin ulcer development in systemic sclerosis patients

Objective. Digital ulcerations are one of the most frequent manifestations of microangiopathy in patients with systemicsclerosis (SSc; scleroderma). The early detection of SSc patients who are at high risk to develop digital ulcers could allowa preventive treatment of these complications with reduction of morbidity and social costs. The aim of our study was todevelop a capillaroscopic skin ulcer risk index (CSURI) that can predict the onset of new digital ulcers by using nailfoldvideocapillaroscopy (NVC) in patients with SSc.Methods. We performed NVC in 120 consecutive unselected patients with SSc (13 men, 107 women, mean SD age56.1 13.4 years, mean SD SSc duration 44.7 60.7 months) to assess the total number of capillaries in the distal row(N), maximum loop diameter (D), number of megacapillaries (M), and the M:N ratio.Results. Within 3 months since NVC examination, 35 of 120 patients experienced digital ulcers. A significant associationbetween ischemic lesions and the M:N ratio, N, and D was observed; the combination of these parameters allowed us todevelop the CSURI, which is characterized by the formula D M:N2. A receiver operating characteristic curve analysisshowed an area under the curve of 0.926 for ulcer appearance, with specificity and sensitivity of 85.9% and 94.3%,respectively, at the cutoff value of 2.94. Interestingly, 33 of 35 patients with new skin ulcers had a CSURI >2.94, but only2 of 35 had a CSURI <2.94.Conclusion. The proposed CSURI may represent a novel tool with the ability to predict the development of digital ulcersin patients with scleroderma.