IgG4-Related Disease in Childhood: Clinical Presentation, Management, and Diagnostic Challenges.

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory disorder primarily affecting adults. The disease in pediatric age is unusual and preferentially affects adolescents. In contrast to adults, who commonly exhibit the involvement of multiple organs simultaneously or sequentially over time, young patients tend to present with a localized disease, typically affecting the orbits. Proptosis, ptosis, diplopia, and restricted eye movement may be observed in these patients. Symptoms are proteiform, and the disease is chronic and indolent with a relapsing-remitting course. Diagnostic criteria have been developed for adults, which may not fully capture the pediatric disease phenotype. If untreated or poorly managed, IgG4-RD can lead to progressive fibrosis and scarring of affected organs, potentially causing irreversible damage. We conducted a narrative review using the IMRAD approach, presenting a nonsystematic analysis of the literature on pediatric IgG4-RD. Original papers, case reports/series, and relevant reviews in English were selected from PubMed, EMBASE, and Web of Science up to January 2024. Keywords included "IgG4-Related Disease" and "pediatric" and, additionally, we presented two original pediatric cases. Our purpose is to offer an overview of IgG4-RD manifestations, and challenges in diagnosing and managing this rare condition in children.