Background Rheumatoid arthritis (RA) is a systemic inflammatory disease characterized by progressive destruction of inflamed joints leading to severe disability and functional loss. Systemic sclerosis is a multisystem autoimmune disease characterized by vasculopathy, diffuse fibrosis of skin and various internal organs. Pain is usually an overlooked entity in patients with SSc compared to RA.

Objectives To compare pain characteristics particularly in terms of neuropathic pain (NeP) and to assess the possible impact of neuropathic component on functioning, physical and mental components of health related quality of life (HRQoL) in patients with RA and SSc.

Methods Patients who met ACR/EULAR criteria for SSc and RA were recruited. Patients with prior diagnosis or taking medications for NeP, mood disorders, uncontrolled diabetes or neurological disorders or taking any biologic agents for their treatments were excluded. Patients were examined and evaluated for disease specific and generic outcome measures including disease activity parameters, physical functions, psychological status and health related quality of life measures (SF-36; HAQ; Hospital Anxiety and Depresson Scale, HADS). The DN4 interview and PainDetect questionnaire were applied by the same experienced physician who was blind to patients clinical and outcome data. Patients with a score ≥4 in DN4 were considered as “probable NeP”; between 13–18 or ≥19 in PainDetect were considered as “possible” or “likely NeP”, respectively.

Results Fifty patients (44 F, 6 M) with SSc and fifty-one (45 F, 6 M) with RA were included. Patients had similar age and similar gender, educational and smoking status, as well as functioning and HRQoL. However, patients with RA declared more severe pain on VAS-pain (p=0.012), and higher body mass index than patients with SSc (p<0.0001). NeP component was similar in patients with SSc vs RA. NeP component was detected 42.0% in SSc, and 47.1% in RA (p>0.05) according to DN4 scores. According to PainDetect questionnaire, possible NeP was detected in 12.0% vs 15.7%, whereas 16.0% vs 17.6% had likely NeP in SSc and RA, respectively (p>0.05). Neuropathic characteristics of pain were similar in SSc and RA defined as burning, electric shock, tingling, pins and needles, and itching except for numbness and painful cold which were significantly more prevalent in patients with SSc (%50.0 vs %25.5, p=0.011 and %50.0 vs %19.6, p=0.001; respectively). In SSc patients with or without NeP component had similar functioning and HRQoL measures. However, having NeP component revealed a heavier burden of disease regarding functioning, HRQoL and psychometric components patients with RA.

Conclusions The NeP component was similar in patients with RA and SSc. However NeP was associated a heavier burden of disease in patients with RA.

Disclosure of Interest None declared