Background Chronic pain is experienced by many patients with joint disease but underlying pain phenotypes including impact of concomitant fibromyalgia (cFM) have not been investigated in patients with psoriatic arthritis (PsA) and hand osteoarthritis (hand-OA).

Objectives To investigate pain parameters (quantitative sensory testing) in patients with hand-OA and PsA using pressure pain thresholds (PPT), temporal summation of pain (TSP) and conditioned pain modulation (CPM) compared with healthy controls. Furthermore, to explore whether alternations in underlying pain mechanisms and psychological factors are associated with cFM compared to those patients without.

Methods Patients with verified PsA or hand-OA and healthy controls underwent quantitative sensory testing using hand-held and cuff pressure algometry to measure PPT, TSP and CPM. Psychosocial factors were assessed via the Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Pittsburgh Sleep Quality Index, and disability was assessed via the Health Assessment Questionnaire Disability Index and pain quality via the painDETECT questionnaire. cFM was identified using the revised 2016 American College of Rheumatology criteria.

Results A total of 75 patients with hand-OA, 58 patients with PsA and 20 controls were included. Patients with hand-OA or PsA had statistically significant lower PPTs and CPM, and greater TSP than controls and greater psychosocial impact. Limiting the analysis to patients without cFM yielded a similar result. Patients with cFM (58%) had greater scores of depression, anxiety, catastrophizing, disability and reduced sleep quality when compared to patients without cFM. Additionally, in cFM the TSP and painDETECT scores were higher compared to patients without cFM.

Conclusion Patients with hand-OA and PsA experienced a greater degree of pain facilitation and psychosocial impact when compared with controls. Patients with cFM had greater TSP, painDETECT, disability, catastrophizing and reduced sleep quality, than patients without, indicating greater degree of sensitisation, psychosocial burden, and disability.

Disclosure of Interests Jonathan Vela: None declared, Lene Dreyer Grant/research support from: Grant from BMS

Honorarium from Eli Lilly, Galderma and Janssen, Kristian Kjær Petersen: None declared, Lars Arent-Nielsen: None declared, Salome Kristensen: None declared