A Rare Case of Acute Portal Vein Thrombosis in a Child with Relapse of Steroid-Dependent Nephrotic Syndrome

Venous thromboembolism is a recognized but underdiagnosed complication of pediatric nephrotic syndrome (NS). While renal vein thrombosis and cerebral venous sinus thrombosis are more frequently reported, portal vein thrombosis (PVT) is exceedingly rare and may result in significant morbidity if not promptly identified. We report a 9-year-old boy with steroid-dependent nephrotic syndrome (SDNS) who presented with prolonged vomiting, diarrhea, abdominal distension, and altered mentation. Investigations revealed relapse of NS with profound proteinuria, hypoalbuminemia, refractory electrolyte disturbances, and acute PVT confirmed on abdominal ultrasonography with Doppler. The child required anticoagulation with low-molecular-weight heparin, escalation of antibiotics, albumin infusions, and metabolic correction in the pediatric intensive care unit. He showed gradual recovery with the normalization of electrolytes and resolution of encephalopathy. The patient was discharged on oral anticoagulation and remained clinically stable during follow-up. Subsequent imaging on follow-up revealed partial recanalization of the portal vein. This case underscores PVT as an uncommon yet potentially life-threatening thrombotic complication in relapsing SDNS. Early imaging, timely anticoagulation, and multidisciplinary supportive care are essential for favorable outcomes. Sustained follow-up and adherence to immunosuppressive therapy are critical in preventing relapse-related complications.