SCCM

Systemic Capillary Leak Syndrome (SCLS), also known as Clarkson's disease, is a rare disorder characterized by the acute and recurrent leakage of plasma and other blood components from the circulatory system into the interstitial space. This results in severe hypotension, hemoconcentration, and hypoalbuminemia without a primary cause for capillary hyperpermeability. The exact etiology of SCLS is unknown, but it is thought to involve a transient increase in endothelial permeability. The condition is life-threatening and requires prompt recognition and management.

Etiology and Pathophysiology

The precise cause of SCLS remains unclear, but it is believed to involve an immune-mediated process that leads to episodic capillary hyperpermeability. Several theories suggest the involvement of cytokines, vascular endothelial growth factor (VEGF), and other inflammatory mediators. Some patients have monoclonal gammopathy of undetermined significance (MGUS), suggesting a possible link between plasma cell dyscrasias and SCLS.

Clinical Presentation

Patients with SCLS typically present with episodes of severe hypotension, edema, and hemoconcentration. These episodes, often termed crises, can be precipitated by infections, physical stress, or no identifiable cause. Symptoms may include sudden weight gain, generalized swelling, weakness, fatigue, and in severe cases, shock.

Diagnosis

The diagnosis of SCLS is primarily clinical, supported by laboratory findings of hemoconcentration (elevated hematocrit) and hypoalbuminemia. Imaging studies, such as computed tomography (CT) or magnetic resonance imaging (MRI), may show evidence of widespread edema. A key diagnostic criterion is the exclusion of other causes of capillary leak, such as sepsis or anaphylaxis.

Treatment

Management of SCLS focuses on the acute management of hypovolemic shock and the prevention of recurrent episodes. Intravenous fluids, corticosteroids, and vasopressors may be required during acute crises. Long-term prophylaxis with medications such as theophylline and terbutaline has been reported to reduce the frequency and severity of episodes. Intravenous immunoglobulin (IVIG) therapy has also shown promise in some cases.

Prognosis

The prognosis of SCLS varies. While some patients experience infrequent episodes with full recovery, others may have frequent and severe episodes leading to significant morbidity and mortality. Early recognition and aggressive management are critical to improving outcomes.

Epidemiology

SCLS is an extremely rare disorder, with only a few hundred cases reported in the medical literature. It can occur in individuals of any age but is most commonly diagnosed in middle-aged adults. There is no known gender predilection.

See Also

• Capillary leak syndrome
• Hypovolemic shock
• Monoclonal gammopathy of undetermined significance (MGUS)
• Vascular endothelial growth factor (VEGF)