Abstract
Phlegmasia cerulea dolens (PCD) is a limb-threatening venous disorder involving massive proximal venous thrombosis. The clinical manifestations are of oedema, cyanosis and pain of lower extremity. Patients presenting with PCD have an underlying pathological condition that predisposes to the thrombotic process. We report a diabetic patient who presented with PCD and septicaemia due to a spontaneous psoas abscess. Anticoagulation with heparin and treatment of the underlying psoas abscess led to complete resolution of symptoms. An understanding of the underlying pathological process responsible is vital to early recognition and successful outcome in this rare limb- and life-threatening venous disorder.