A mild and transient case of Influenza-Associated Encephalopathy in a child: Diagnostic and Clinical Challenges

Background: Influenza-associated Encephalopathy (IAE) is a rare but serious complication of influenza infection, predominantly affecting children. While most reported cases present with moderate to severe neurological symptoms, mild and self-limiting forms remain under-recognized. Case Presentation: We report the case of a previously healthy ۹-year-old boy who presented with fever, lethargy, behavioral changes, and two episodes of focal seizures without awareness during the course of an influenza-like illness. Laboratory evaluations were notable for leukopenia and elevated D-dimer levels. Neuroimaging revealed a medial right temporal arachnoid cyst, and cerebrospinal fluid (CSF) analysis showed mild pleocytosis with positive Influenza A PCR. Electroencephalography was normal. The patient was managed with intravenous antibiotics, antiviral therapy, and supportive care. His symptoms resolved rapidly without neurological sequelae, and he made a complete recovery. Conclusion: This case highlights a rare, mild, and transient presentation of IAE in a school-aged child. Awareness of such atypical and self-limiting forms can assist clinicians in timely diagnosis and avoid unnecessary interventions. Influenza- associated neurological symptoms should be considered even in the absence of severe systemic or respiratory manifestations.