Immunoglobulin G4-related disease (IgG4-RD) is a systemic fibro-inflammatory disease that affects several body regions and has an unknown pathophysiological mechanism. If left untreated, fibrosis and irreparable organ damage might develop. IgG4-RD has only been described in adults. Thus, doctors are unfamiliar with it. The systematic review of the literature summarized all studies published on IgG4-RD in children, intending to raise awareness of the condition in pediatrics and emphasize the disease’s overall clinical presentation. For case reports on IgG4-RD in children, a comprehensive literature search was conducted using Embase, Medline, Web-of-Science, PubMed publisher, Cochrane, and Google Scholar.

The search yielded 22 case reports, including 25 cases of IgG4-RD in children, out of a total of 740 publications. On average, the children were 13 years old, with 64% being girls. 

The most common diagnoses were IgG4-related orbital illness (44%) and autoimmune pancreatitis type 1/IgG4-related pancreatitis (12%). Other signs such as pulmonary manifestations, cholangitis, and lymphadenopathy were seen less frequently. Almost all of the instances had histology evidence. Prednisone was the initial line of treatment in 83% of cases, resulting in a good clinical response. In 43% of the patients requiring treatment, maintenance therapy with steroid-sparing drugs was indicated. Mycophenolate mofetil, azathioprine, and methotrexate, all disease-modifying rheumatic drugs (DMARDs), were effective in approximately half of the patients’ rituximab was effective in all four. IgG4-RD is a disorder that few clinicians are familiar with in children. However, few cases have been reported. Prednisone was the initial line of treatment in most patients, resulting in disease remission. Alternative effective steroid-sparing medications include DMARDs and rituximab, with the latter having more good data.