Overlap Syndromes in Pediatric Rheumatology Practice

Oshlianska O.^1,2, Nadtochiy T.², Yats K.²

• ¹National University of Health Care of Ukraine named after P.L. Shupyka, Kyiv
• ²SI «O.M. Lukyanova Institute of Pediatrics, Obstetrics and Gynecology National Academy of Medical Sciences of Ukraine», Kyiv

Summary. Many systemic connective tissue diseases exhibit similar signs and symptoms, posing challenges in diagnosing specific rheumatic conditions. Overlap syndrome, characterized by clinical features of at least two other conditions, presents a diagnostic conundrum. Currently, there is no unified approach or specific treatment recommendations. BMJ Best Practice (2022) suggests adopting a syndromic approach to therapy. This article presents a prospective observational study conducted at a pediatric rheumatology clinic from 2012 to 2023. Out of a total of 3565 children with rheumatic diseases, 16 had overlap syndrome. Clinically, the most common combination of symptoms was with SSc: JDM-SSc — 4 cases, SLE-SSc — 2 cases, SV-SSc — 1 case, JIA-SSc — 3 cases. Five patients met the criteria for Sharpe syndrome, and one showed manifestations of SV+IBD. Therapy included systemic CS in 14 patients, MTX in 8, MMF in 1, AZA in 1, hydroxychloroquine in 4, and CP in 3. Four patients required repeated replacement of DMARDs. The majority (15 patients) achieved medical remission within 6 months, despite high ANA titers in 2 patients, and one case was fatal.