Fulminant Pediatric Viral Rhabdomyolysis with Extreme HyperCKemia, Multiorgan Dysfunction Syndrome, and Complete Renal Recovery without Kidney Replacement Therapy: A Case Report and Literature Review

Abstract

Background: Viral-associated rhabdomyolysis is an important but uncommon cause of paediatric intensive care unit (PICU) admission. Although most cases of benign acute childhood myositis are self-limited, severe viral rhabdomyolysis may progress to multiorgan dysfunction syndrome (MODS), acute kidney injury (AKI), electrolyte disturbances, and respiratory failure. Extreme hyperCKemia exceeding 100,000 U/L is rare in children and remains poorly correlated with renal outcomes. Case Presentation: A 10-year-old girl with autism spectrum disorder presented with viral prodromal symptoms followed by respiratory distress, cola-coloured urine, and progressive systemic illness. She required PICU admission for MODS characterised by respiratory failure requiring high-flow nasal cannula (HFNC), non-oliguric AKI, thrombocytopenia, leukopenia, transaminitis, and fulminant rhabdomyolysis. Peak creatine kinase (CK) was approximately 420,000 U/L, with serum myoglobin >3,000 ng/mL. Despite extreme hyperCKemia, urine output was preserved throughout the illness, and renal dysfunction resolved within three days without dialysis. Serial monitoring demonstrated gradual normalisation of CK, myoglobin, renal function, and liver enzymes with supportive management alone. Discussion: This case highlights the dissociation between CK magnitude and renal outcome in paediatric rhabdomyolysis. Early recognition, preserved urine output, prompt fluid resuscitation, and intensive supportive care likely contributed to favourable recovery despite severe muscle injury. Mechanisms of viral-induced myonecrosis, pigment nephropathy, and MODS are discussed, along with contemporary controversies regarding bicarbonate therapy, mannitol, and extracorporeal therapies. Conclusion: Fulminant viral-associated rhabdomyolysis can present with MODS and extreme hyperCKemia in children yet still demonstrate excellent recovery with early PICU-directed supportive care. Recognition of cola-coloured urine and severe transaminitis during viral illness is essential for timely diagnosis and prevention of irreversible organ injury.