[Syndrome of increased idiopathic capillary permeability (Clarkson's syndrome)]

Idiopathic systemic capillary leak syndrome (Clarkson's disease) is characterized by recurring attacks or increased capillary permeability, resulting in severe hypovolemic shock due to plasma extravasation from the intravascular compartment. Additional laboratory features include association with a monoclonal gammopathy, extreme hemoconcentration and hypoalbuminemia. The underlying cause is not known and there have been fewer than 40 cases reported. It affects people aged 30-40 years and has a high mortality, with only six of 25 patients surviving for more than 5 years. Marked thirst is noted early in the attack and profound muscle weakness, anorexia; nausea, and vomiting are present in all patients, especially so during the course of an attack. Generally, oedema appeared several hours or days before the onset of shock. The total duration of illness varied from six months to seven years. An unknown trigger causes a temporary increase in the macromolecular permeability in the capillary bed of skeletal muscle and connective tissue. The syndrome of rhabdomyolysis includes myalgia, swelling and weakness of the involved muscle groups, pigmenturia, and leakage of myoglobin and CK into the serum. Different treatments have been tried, including plasmapheresis, steroids, epoprostenol, salbutamol and Gingko biloba extract with success in some cases. Treatment with corticosteroids should be considered for prevention of attacks in the systemic capillary leak syndrome.