Exploratory study to identify mechanical factors that may contribute to toe dactylitis in patients with psoriatic arthritis

Background Dactylitis (sausage digit) is one of the most commonly reported features of psoriatic arthritis (PsA), the second most common inflammatory arthritis after rheumatoid arthritis (RA). It has been hypothesised that dactylitis is a functional enthesitis at the proximal interphalangeal joints (hands and feet), causing multiple pathologies to varying levels of severity. Dactylitis results in synovitis, tenosynovitis, bone and soft tissue oedema to the digit, described as tender and non-tender dactylitis. Trauma and physical insult to the digit have been suggested as a possible cause. The aim of this study was to explore the mechanical factors that may contribute to toe dactylitis in patients with PsA.