Background The term of erosive arthritis is borrowed from rheumatoid arthritis and is needed for complete evaluation of a patient with PA (Psoriatic Arthritis). Plain radiography is still the gold standard used for assessing bone changes in the peripheral joints for medium and long term evaluation of the disease progression in PA. Up to 67% of patients with established PA have plain radiographic manifestations of articular disease (1). The Larsen score, modified Steinbroker score, and Sharp score have been validated in established PA, and a modified Sharp method have been validated in early PA (2,3). So, we have tools to give us good infos, but it is not clear if these patients have significant differences from others.

Objectives To identify the profile of patients with erosive PA for appropiate adjustment of therapy

Methods 88 patients were examined in our clinic between octomber 2011 and december 2012, having mean age 55.53±11.06 years, 59.1% been female, classified according CASPAR criteria. The assessment had included demographic dates, medical history, a clinical assessment for skin disease (PASI score) and joint disease (number of tender joints, swollen joints, functional score like HAQ), a biological assessment (ESR, C reactive protein, rheumatoid factor, CCP-antibodies) and an imagistical assessment. We performed ultrasound assessment for small joints of the hands and radiological assessment of peripheral joints (hand, feet, according modified Sharp-van der Heijde score) (4).

Results Of 88 patients with PA only 31.8% have erosive disease. Erosive disease is present in all clinical forms of PA regardless of onset (olygoarticular 72.7%, axial 40%, polyarticular 83.3%, mutilans 100%, distal interphalangian 50%, p=0.06). The patients with erosive disease had more familial history of psoriasis (35.6%, p=0.02) and spondyloarthritis (24.4%, p=0.009), more nail involvement (22.2%, p=0.08), more skin involvement (PASI=7.56±9.97, p=0.09), more joint involvement (tender joints p=0.09, swollen joints p=0.01) producing peripheral disability (HAQ=1.44±0.84, p=0.04). Radiological bone erosions were found also on ultrasound examination, 53.7% of patients with erosive radiological disease having erosive abnormalities on ultrasound (p=0.01). Besides this, there are linear correlation between duration of psoriasis (15.42±15.73 years, p=0.03, r=0.43), duration of PA (6.75±5.21 years, p=0.02, r=0.46), active clinical disease (tender joints p=0.04, r=0.41; swollen joints p=0.06, r=0.36) and seropositivity (titer of rheumatoid factor=19.99±30 ui/ml, p=0.02, r=0.4 7; titer of CCP antibody=48.69±128 ui/ml,p=0.008, r=0.55).

Conclusions The patients with erosive PA have older disease, more joint activity and disability, more skin activity, but also seropositivity for rheumatoid factor and CCP antibodies.

References

1. Gladman DD et al, PA-an analysis of 220 patents, QJMed 1987; 62:127-141

2. Gladman DD, Natural history of PA, Baillieres Clin Rheumatol 1994; 8: 379-394

3. Gladman DD et al,Psoriatic spondyloarthropathy in men and women: a clinical, radiographic and HLA study, Clin Invest Med 1992; 15: 371-375

4. van der Heijde D, JRheumatol, How to read Radiographs According to the Sharp van der Heijde Method,1999;26:743-5

Disclosure of Interest None declared

DOI 10.1136/annrheumdis-2014-eular.3365