Chronic systemic capillary leak syndrome with monoclonal kappa light chain gammopathy responsive to intravenous immunoglobulin: a case report

Abstract Background Systemic capillary leak syndrome (SCLS) is a rare disorder characterized by transient plasma extravasation due to endothelial barrier dysfunction. It may occur idiopathically (ISCLS) or in association with monoclonal gammopathy (MG-CLS), a form also known as Clarkson’s disease. Case presentation We describe a 39-year-old woman with a 15-year history of episodic, symmetric limb edema and profuse sweating, unresponsive to antihistamines or corticosteroids over several years. Episodes were chronic and lacked hypotension or pruritus. Laboratory workup revealed monoclonal kappa light chain gammopathy and borderline hemoconcentration. Monthly high-dose intravenous immunoglobulin (IVIG, 2 g/kg) was initiated. Improvement was noted by the fourth infusion, with complete resolution of swelling and marked reduction in sweating after five months of therapy. IVIG was well tolerated apart from mild infusion-related headache. Conclusions This case illustrates that MG-CLS may present as a chronic disorder without the classic triad and may respond favorably to IVIG. In selected patients with mild or atypical presentations, a therapeutic trial of IVIG may be considered.