Background Pain is a common symptom in all arthritides, and remains a problem also with better treatment options. In axial spondyloarthritis (ax-SpA), data on chronic pain remain scarce.
Objectives To study pain distribution, duration and intensity in ax-SpA, and relate this to disease status and measurement of pressure pain sensitivity.
Methods Consecutive patients (n=115) with clinical ax-SpA diagnoses (ankylosing spondylitis (AS) or undifferentiated axial spondyloarthritis (USpA)) were examined and answered pain questionnaires. Patients were categorised as having no chronic pain (NCP), chronic regional pain (CRP) or chronic widespread pain (CWP). Pressure pain sensitivity was assessed by computerized pneumatic cuff pressure algometry (CPA) on the dominant lower leg, and pain threshold, pain tolerance and temporal summation (assessed by the temporal summation index, TSI) were recorded. Differences in disease status and pressure pain sensitivity between patients with CWP versus NCP were assessed (Chi-square or Mann-Whitney U-test). Pressure pain sensitivity was also compared between patients with/without unacceptable pain levels (VAS pain >40 versus ≤40; Mann-Whitney U-test).
Results Fifty percent of patients reported CWP, irrespective of clinical diagnosis (AS 47%, USpA 53%), and more women than men reported CWP (59% versus 37%, p<0.001). Only 18% of all patients reported NCP. Overall, higher disease activity, pain intensity, worse fatigue, global health and function were observed among patients with CWP compared to those with NCP. There was a trend towards lower pain tolerance in patients with CWP compared to NCP (Table). Lower pain tolerance and higher TSI scores were observed among patients reporting VAS pain >40 versus those with VAS pain scores ≤40 ((mean (SD)) 51.9 (21.2) versus 68.1 (28.1), p=0.007; 0.73 (0.60) versus 0.55 (0.59), p=0.045).
Conclusions In this population-based, cross-sectional study of established ax-SpA, chronic widespread pain was common, affecting 50% of the patients and generally associated with higher disease activity and worse function. CPA shows promising results regarding assessment of pain sensitivity, although larger studies are needed for more conclusive results.
Acknowledgements Miriam Walsh-Ingelström performing all CPA assessments
Disclosure of Interest E. Mogard: None declared, T. Olofsson: None declared, A. Bremander: None declared, S. Bergman: None declared, L.-E. Kristensen Grant/research support from: Oak Foundation, Consultant for: AbbVie, Celgene, BMS, MSD, Novartis, Pfizer, UCB, J. Kvistgaard Olsen: None declared, J. Wallman Consultant for: Celgene, Novartis, UCB, E. Lindqvist: None declared