Background Spondylarthritis are entities that are pathogenetically distinct from rheumatoid arthritis and have some characteristically features like inflammation of bony insertion for tendons and ligaments (enthesopathy), which is considered a hallmark of the disease(1). McGonagle et al proposed that an enthesitis is the primary lesion in psoriatic arthritis and it might be a activity index of this disease (3). Enthesitis is best visualised by ultrasonography or MRI and is only detected on radiography after ossification process has occurred (4).

Objectives to assess enthesitis in patients with psoriatic spondylarthritis comparing with a control group with ankylosing spondylitis.

Methods We had included 29 patients with psoriatic spondylarthritis (with axial involvement) using CASPAR criteria followed in our rheumatology department between September 2011 and January 2012. The assessment included disease activity (pain score, patient global assessment, tender joints, swollen joint, BASDAI score, ESR, CRP), functionality assessment (BASFI score) and the ultrasound assessment of enthesitis (MASEI score) (5). The control group (22 patients) with ankylosing spondylitis, diagnosed by using NewYork criteria, were assessed on the same manner.

Results All 51 eligible patients from two groups were evaluated. There were no significant differences in age mediana, biological therapy (20.7% in PA, 17.6% in AS group) but were in gender ratio (male of PA 58.6%, of AS 86.4%), DMARD-therapy(86.2% in PA, 41.2% in AS) or in familial history of psoriasis (17.2% in study group). There are no differences in MASEI score between groups (2.10±1.93, 1.91±2.52 respectivelly) in contrast to BASDAI (p=0.006), BASFI score (p=0.011) and to clinical variables (like tender joints, swollen joints). The MASEI score had correlated in all patients only with VAS (p=0.08, r=0.2), swollen joints (p=0.06, r=0.3) and CRP (p=0.03, r=0.3), but in psoriatic arthritis only with clinical variables, like VAS (0=0.05, r=0.3) and BASDAI score (p=0.08. r=0.3).

Conclusions The enthesitis mirrors the activity of disease and influences the pain scores like VAS or BASDAI, but is not more present than in patients with ankylosing spondylitis.

1. Koopman WJ,Moreland WL, Arthritis and Allied Conditions, 2004, Lippincott Edition

2. McGonagle et al, PA: a unified concept twenty years on; ArthritisRheum 1999; 42: 1080-86

3. Bijlsma JW et al., Eular Compendium of Rheumatic Diseases, 2009, BMJ Publishing Group

4. De Miguel E et al, Diagnostic accuracy of enthesis ultrasound in the diagnosis of early spondyloarthritis, AnnRheumDis 2011, 70: 434-9

Disclosure of Interest None Declared