New Approach May Detect Digital Ulcer Risk in Systemic Sclerosis Patients

A novel way of identifying systemic sclerosis (SSc) patients with a high likelihood of digital ulcers could lead to them being given preventive therapy that may greatly benefit the quality and length of their lives. The categorization system is detailed in a study titled “Elucidating the burden of recurrent and chronic digital ulcers in systemic sclerosis: long-term results from the DUO Registry,” published in the journal Annals of the Rheumatic Diseases.

Digital ulcers (DUs) are a common external symptom of vasculopathy (conditions affecting the blood vessels) in scleroderma, occurring in up to half of patients with the disease. Several studies have shown that DUs are associated with significant burden, or complications, including infection, gangrene, and amputation, leading to pain, disability, increased hospitalizations, cardiovascular aggravation, and lower survival rates.

Previous studies have proposed various categorizations for DUs, however their clinical value has been limited. Therefore, the need exists for a new system of categorization that better identifies patients at risk of high disease burden and requiring more complex disease management.

The research team reviewed patient data from the Digital Ulcers Outcome (DUO) Registry to assess the impact of DUs associated with systemic sclerosis (SSc-DUs) in a clinical setting. The DUO Registry, started in 2008, was an international, prospective, observational study that collected data from European patients with a history of SSc-DUs. Enrolled patients underwent at least two years of observation and at least three follow-up visits during the study period, from April 1, 2008, to Nov. 19, 2013. The authors recorded DU-associated complications during the follow-up period. Work and daily activity impairment were measured using a functional assessment questionnaire completed by patients post-observation period. Potential factors that could predict incident complications were identified in patients with chronic DUs.

The authors identified four DU occurrence categories among 1,459 patients: no-DU (33.2%), episodic (9.4%), recurrent (46.2%) and chronic (11.2%), based on the timing of new ulcer development rather than on DU activity. During the observation period, chronic DU patients had the highest rate of incident complications, work impairment, and hospitalizations compared with those in other groups. Independent factors associated with incident complications included gastrointestinal manifestations and previous soft tissue infection. Overall, the findings confirmed that DUs are a considerable burden in patients with SSc and suggested that more severely affected subgroups can be identified in the clinic.

The four categories proposed here may impact the design of future clinical trials, and are complementary to other classifications based on the origin of DUs (pure, calcinosis, digital pitting scar, gangrene). These categories show striking variation in clinical impact and are highly relevant to clinical practice.

The authors believe these four novel categories may better define the level of disease burden associated with DUs and could be useful in identifying groups of patients from a prognostic perspective.