Peripheral spondyloarthritis: Concept, diagnosis and treatment.

Peripheral spondyloarthritis refers to spondyloarthritis with predominant peripheral (arthritis, enthesitis or dactylitis) involvement. Diagnosis can be challenging, particularly in the absence of SpA extra-articular manifestations such as uveitis, psoriasis or inflammatory bowel disease. Evaluation of disease activity should always include assessment of objective signs of inflammation, particularly in the presence of enthesitis as the sole peripheral manifestation, mainly due to the potential misdiagnosis with fibromyalgia tender points. Several recommendations for management/treatment of psoriatic arthritis have been published by EULAR and GRAPPA but none for peripheral SpA in general. NSAIDs and glucocorticoids are recommended as the first step of treatment in all peripheral manifestations, while conventional synthetic (cs) DMARDs seem only efficacious in arthritis. Several biologics and targeted synthetic (ts) DMARDs (TNFi, anti-IL17 and JAK-inhibitors) have been proven to be efficacious in peripheral involvement in PsA (arthritis and enthesitis), but studies on peripheral SpA are lacking.