Digital ulcers and outcomes assessment in scleroderma

Ischaemic ulcerations of the fingertips are common in SSc and a source of pain and disability. Healing has been demonstrated with intravenous iloprost and two studies with bosentan have demonstrated reduction in the occurrence of new digital ulcers (DUs) over 46 months of treatment. Both bosentan studies showed no benefit in healing DU and because of this, net DU burden is no different between drug and placebo and accordingly secondary measures of outcome including pain and hand functionality are inconsistently affected. While it is likely an artefact, it remains unclear that current outcome measures including the Scleroderma Health Assessment Questionnaire (SHAQ), the UK Functional Score and the Michigan Hand Questionnaire are sensitive to change in the domain of digital ischaemia. Major events including amputation and hospitalization occur too infrequently to serve as practical measures of outcome in trials. Future studies of DU therapies will benefit from development of an ulcer-specific measure of outcome.