Raynaud’s phenomenon (RP) is present in more than 95% of patients with systemic sclerosis (SSc). Its frequency and severity in combination with the presence of digital ulcers affect the quality of life of patients.1 Although the aetiology of RP is multifactorial, endothelin-1 has been suggested to play a role in its pathogenesis.2 Bosentan, an endothelin-1 receptor antagonist, has been shown to be effective in preventing the occurrence of new digital ulcers when compared with placebo.3

Against this background, we hypothesized that bosentan can be a useful and effective strategy in SSc patients with RP. Therefore we assessed the effects of bosentan …