Systemic Capillary Leak Syndrome as a Rare, Potentially Fatal Complication of COVID-19: A Case Report and Literature Review.

Systemic capillary leak syndrome (SCLS), also known as Clarkson's disease, is a rare and potentially lethal condition characterized by hypotension, hemoconcentration, and hypoalbuminemia; however, the cause of SCLS is still uncertain. We present the case of a 62-year-old male with flu-like symptoms who presented to the emergency department with shock. Initial evaluation revealed hemoconcentration, hypoalbuminemia, acute kidney failure, and positive polymerase chain reaction (PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Despite aggressive fluid resuscitation, the shock persisted, and the patient's condition deteriorated. After ruling out ischemia and septic shock, the patient was diagnosed with coronavirus disease 2019 (COVID-19)-associated SCLS. Treatment with remdesivir and intravenous immunoglobulin (IVIG), along with the restoration of intravascular volume, led to the gradual improvement of the patient's condition. The patient experienced pulmonary edema, which was managed by correcting the fluid balance through continuous hemodiafiltration. Eventually, the patient recovered without any residual organ complications. SCLS is often misdiagnosed because of its rarity and non-specific symptoms. Accurate diagnosis and understanding of the disease's pathophysiology are crucial for effective management. This report contributes to the existing literature by presenting a case of COVID-19-associated SCLS and emphasizes the need for further research on its occurrence and outcomes.