Abstract
CASE REPORTS: Three patients-two with Wegener's granulomatosis and one with an overlap syndrome of rheumatoid vasculitis, systemic lupus erythematosus, and antiphospholipid syndrome-are described. All patients experienced a sudden onset of Raynaud's phenomenon or acrocyanosis when they had a flare of their disease. DISCUSSION: Ultrasonography (US) showed dark (hypoechoic) arteries without colour signals, resembling the US pattern of embolism. In contrast, US in patients with systemic sclerosis is entirely different, delineating a smaller artery lumen, reduced pulsation, and thickened, slightly hyperechoic artery walls.