Prevalence and clinical characteristics of dactylitis in spondylarthritis: a descriptive analysis of 275 patients.

TLDR: Dactylitis is a frequent manifestation in SpA particularly in peripheral disease and it may be the first manifestation of the disease with localisation being more frequent in the toes.

Abstract: OBJECTIVES Dactylitis is a common but little studied feature of spondylarthritis (SpA). Our objective was to assess the prevalence of dactylitis among a cohort of patients with spondylarthritis in a tertiary care centre and to describe the clinical characteristics of dactylitis. METHODS This was a prospective single centre observational study carried out in 2010. The patients included had been diagnosed as having definite SpA based on Amo's criteria. Each patient was interviewed by a physician. The data collected included prevalence of dactylitis and its clinical characteristics, effectiveness of the different treatments, and association with severe manifestations of SpA, and analysed by descriptive analysis. RESULTS 275 consecutive SpA patients were assessed: mean age 43.2±13.5 years, mean disease duration 14.0±11.8 years, 169 (61.4%) were men. In all, 59 patients (21.5%) suffered from SpA-associated dactylitis. The localisation of dactylitis was toes in 46 patients (78.0%) and/or fingers in 25 patients (42.4%). The most frequent localisations were the second toe and the second finger. Dactylitis was the first symptom of SpA in 14 patients (5.1%), and 28.8% (n=17) of dactylitis appeared within the first 5 years of disease. Dactylitis was present in 35.1% (n=13) of patients with undifferenciated SpA and in 30.6% (n=15) of patients with psoriatic arthritis. It was significantly associated with history of peripheral arthritis or heel pain. In our population, there was no correlation between dactylitis and HLA B27 status or sex and it was not a marker of severity of disease. CONCLUSIONS Dactylitis is a frequent manifestation in SpA (21.5%) particularly in peripheral disease and it may be the first manifestation of the disease with localisation being more frequent in the toes.