Transient Post-infectious Multisystem Inflammatory Overlap Presentation in a Pediatric Patient With Neurological, Hepatic, Gastrointestinal, and Autoimmune Manifestations: A Rare Case From Azerbaijan.

Pediatric multisystem inflammatory overlap presentations represent a significant diagnostic dilemma. These transient, reactive conditions frequently mimic severe, chronic autoimmune, neoplastic, or demyelinating disorders, leading to potential diagnostic confusion. Following an antecedent respiratory infection, post-infectious immune activation can manifest as a complex cluster of concurrent multi-organ findings, including incidental neuroinflammatory imaging changes, hepatic steatosis, gastrointestinal inflammation, and transient autoantibody positivity. Distinguishing these benign, self-limiting post-infectious responses from established systemic disease is challenging, as radiological and laboratory anomalies often appear disproportionate to the patient's clinical status. Recognizing transient post-infectious overlap phenotypes is essential to prevent overtreatment, unnecessary invasive interventions, and inappropriate long-term immunosuppressive therapy. A conservative management strategy supported by systematic, multidisciplinary monitoring and careful clinical correlation, rather than relying solely on isolated laboratory or imaging markers, ensures favorable clinical outcomes and confirms the benign nature of these syndromes. This case underscores that transient post-infectious inflammatory changes can closely mimic severe chronic pathology in pediatric populations. Systematic evaluation and cautious interpretation of isolated autoantibody positivity and incidental radiological findings are essential to prevent unnecessary invasive interventions and overtreatment while ensuring appropriate clinical monitoring.