Background/Objectives: Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is a common autoimmune encephalitis affecting children and adolescents. Its development has been associated with preceding or concomitant infections, particularly herpes simplex virus type 1 (HSV-1). This scoping review characterized the association between infections and pediatric anti-NMDAR encephalitis, focusing on epidemiology, pathophysiology, clinical presentation, treatment, and prognosis from January 2020 to August 2025. Methods: A scoping review was conducted according to the Joanna Briggs Institute (JBI) framework. PubMed was systematically searched using the terms NMDAR encephalitis AND infections AND children. Of 110 identified records, 13 studies met the predefined eligibility criteria. Results: HSV-1 was the most consistently reported infectious association, particularly in younger children. Clinical phenotype varied with age, with neurological manifestations predominating in younger children and psychiatric, behavioral, and cognitive symptoms becoming more prominent in adolescents. HSV-associated cases, particularly following extensive HSV-related brain injury, were associated with greater residual neurological morbidity and less favorable long-term outcomes. Other infectious agents, including SARS-CoV-2, respiratory syncytial virus, influenza B, and norovirus, were reported less frequently, with limited evidence regarding their impact on disease course. Immunotherapeutic strategies were generally similar irrespective of preceding infection, although active or treatment-associated infections could influence treatment timing, sequencing, and infectious-risk considerations. Earlier immunotherapy was associated with more favorable neurological recovery. Conclusions: Infectious exposures, particularly HSV-1, appear to be associated with pediatric anti-NMDAR encephalitis, although causality cannot be established from the predominantly retrospective and case-based literature. Prospective, multicenter studies using standardized diagnostic and outcome measures are needed to clarify the infection–autoimmunity relationship and optimize early recognition and management.

Myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) is a distinct immune-mediated demyelinating central nervous system disorder, frequently presenting as optic neuritis in children and adolescents. Conversely, aquaporin-4 antibody-positive neuromyelitis optica spectrum disorder (AQP4-NMOSD) is an astrocytopathy characterized by more severe relapses and greater residual visual impairment. This scoping review, conducted according to PRISMA-ScR and JBI methodology, mapped evidence from 23 studies identified across PubMed and Scopus over the last decade. The objective was to examine the epidemiology, clinical presentation, imaging, serological findings, therapeutic strategies, and visual outcomes of these conditions in pediatric populations. Results indicate that pediatric MOGAD-associated optic neuritis often presents with optic disc swelling and bilateral anterior optic nerve involvement with perineural enhancement on MRI, typically resulting in reversible visual loss. The 2023 MOGAD diagnostic criteria show high performance in children. In contrast, AQP4-associated optic neuromyelitis more commonly involves the posterior optic nerve and chiasm, leading to poorer visual outcomes. Regarding treatment, maintenance intravenous immunoglobulin (IVIG) reduces relapse risk in selected MOGAD cases, while B-cell-depleting regimens are primarily used for relapse prevention in AQP4-positive NMOSD. In conclusion, pediatric optic neuritis in MOGAD and AQP4-associated optic neuromyelitis are distinct phenotypes with differing pathobiology and therapeutic requirements. Early serological confirmation and individualized immunotherapy are crucial for preventing relapses and preserving functional vision in pediatric patients.