Recent advances in childhood vasculitis

Purpose of review The review aims to summarize the recent findings in vasculitis that may have an impact in our understanding or management of these diseases. Recent findings We are learning more about monogenic diseases that closely mimic the pediatric vasculitides. Deficiency of adenosine deaminase 2 can present with a polyarteritis nodosa (PAN)-like picture and should be included in the differential of all pediatric cases of PAN with a family history or in cases with early stroke, or in cases resistant to conventional therapy. Mutations in tumor necrosis factor α-induced protein 3 results in a disease that can present as Behçet disease called haploinsufficiency of A20. In fact, these patients would also fulfill the existing criteria for PAN and Behçet disease, respectively. Additional advances in Behçet disease pathogenesis come from a large genetic study of Turkish Behçet disease using data obtained from genotyping using the Immunochip. This confirmed the HLA-B-51 locus as the most significant association and identified new risk loci. Large Iranian and Japanese cohorts were used as replication cohorts. Best treatment of pediatric vasculitis remains a challenge as we continue to lack controlled studies. There are new reports in treatment on Henoch–Schönlein purpura/Immunoglobulin A vasculitis which is one of our most frequent childhood vasculitides. Small series of new treatments for central nervous system vasculitis and Takayasu disease will also be summarized. Diagnostic criteria have been reassessed in pediatric Behçet disease as well as adult and childhood forms of antineutrophil cytoplasmic antibodies-positive vasculitis. Summary The new pathways defined in monogenic diseases may help us better understand the pathogenesis and may help us design more targeted therapy. Although pediatric cases are being increasingly recognized, the relative rarity of the diseases presents an obstacle for studies. Thus, we can reach conclusive results for their management through multicenter studies only.