Severe Influenza A-Associated Rhabdomyolysis Without Acute Kidney Injury: A Case Report

A 26-year-old man without known chronic illness presented with acute myalgias, fatigue, and tea-colored urine and tested positive for influenza A. Urinalysis showed 3+ blood with one red blood cell per high-power field on microscopy, supporting pigmenturia.Creatine kinase peaked at 292,109 U/L, while serum creatinine remained 0.7-0.9mg/dL throughout hospitalization.He was treated with intravenous isotonic saline, oseltamivir, and serial biochemical monitoring.Symptoms improved, and creatine kinase decreased to 49,878 U/L by discharge without renal replacement therapy.Subsequent myositis antibody testing was negative; however, a family history of similar episodes raised concern for an underlying inherited susceptibility.This case demonstrates that profound influenza-associated muscle injury can occur without documented acute kidney injury and that renal risk should be assessed using serial kidney function, electrolytes, volume status, and urine output rather than creatine kinase magnitude alone.