ABSTRACT
Idiopathic systemic capillary leak syndrome (Clarkson's disease) is characterized by recurring attacks of increased capillary permeability, resulting in severe hypovolemic shock due to plasma extravasation. Additional laboratory features include association with a monoclonal gammopathy, extreme hemoconcentration, and hypoalbuminemia. Rare manifestations of this syndrome are renal damage and rhabdomyolysis due to increased compartment pressure and ischemic myonecrosis. We present the findings in two patients with capillary leak syndrome complicated by severe rhabdomyolysis, in one case leading to acute renal failure. We review therapeutic aspects of this rare syndrome and emphasize the importance of early diagnosis and of prompt and aggressive fluid replacement.