Prevention of Digital Ulcers in Systemic Sclerosis Patients: A Proposal of Risk Chart

Background/Purpose: Systemic sclerosis (SSc) is a connective tissue disease mainly characterized by fibrosis of skin and internal organs and by diffuse microangiopathy, responsible for digital ulcers (DU) in about 50% of patients. Management of DU is very challenging; it includes combined systemic and local treatments. Risk factors for the appearance of scleroderma DU are not defined and data from literature are discordant.Recently, our group proposed a capillaroscopic index (CSURI: Capillaroscopic Skin Ulcer Risk Index), able to identify patients with high risk to develop DU within 3 months from capillaroscopic evaluation, with a positive and negative predictive value of 62.3% and 97.2%, respectively.Aim of the study was to develop a predictive model, including CSURI, demographic, and clinico-serological parameters, in order to estimate the total risk of developing DU over next six months.Methods: One hundred and seventy-two unselected SSc patients (male/female 19/153, limited/diffuse cutaneous SSc 121/51, mean age 53.4 years ± 13.8 SD, mean SSc duration 108.2 months ± 97.8 SD) from 5 Italian Rheumatology Centers were consecutively enrolled. Capillaroscopic parameters were defined and collected according to our previous study. All patients underwent videocapillaroscopy at baseline; 3 and 6 months later patients were investigated for the development of DU.The main demographic, clinical, and serologic features were evaluated for the possible association with the occurrence of DU. Possible correlations among the variables and DU were investigated by multivariate logistic regression.Results: The development of DU was significantly associated with CSURI (Odds Ratio [OR] - 66.8, confidence interval [CI] 17.9 to 248.7; p <0.001), history of previous DU within the last year (OR 5.1, CI 1.7 to 14.9; p= 0.003), and male gender (OR 6.2, CI 1.1 to 34.5; p= 0.039). The proposed risk chart based on these three parameters is reported in the figure (the percentages are referred to the cumulative risk for DU). Conclusion: Among different SSc parameters CSURI, recent history of DU, and male gender showed to be strictly associated with the appearance of DU within the next six months from baseline. Our composite predictive model, which must be opportunely validated, represents an attempt to classify patients with different risk levels to develop DU; a correct patient's classification may optimize the needed pre-emptive and therapeutical strategies.