The impact of the presence of fibromyalgia on fatigue in patients with psoriatic arthritis: comparison with controls

Background Coexisting fibromyalgia (FM) to psoriatic arthritis (PsA) has been identified and it has been associated with more severe symptoms, impaired function, and greater disability. It was aimed to explore the effect of the presence of FM on fatigue in patients with PsA comparing with controls. Methods Fifty patients with PsA and 34 sex-age matched controls were enrolled. In patients; pain was assessed by Visual Analogue Scale, disease activity by DAS-28, enthesitis by The Leeds Enthesitis Index. Fatigue level of all participants was evaluated by Multidimensional Assessment of Fatigue. In all participants, FM was determined according to 2010 American College of Rheumatology criteria. Results Seventeen patients with PsA (34%) and 4 controls (11.8%) were diagnosed with FM and all of them were women. There was significant difference between the patients and controls in terms of presence of FM (p < 0.05). Patients' fatigue scores were significantly higher than controls' (p = 0.001). There were significant differences between the PsA patients with and without FM with regard to gender, enthesitis, DAS-28 and pain scores (p < 0.05); fatigue scores (p < 0.001). The significant effect of the presence of FM on fatigue was found by univariate analysis of variance in patients (p < 0.001). Conclusion It was observed that FM presence and fatigue were more common in PsA patients than controls and comorbid FM had significant effect on fatigue in these patients. Physicians should be aware of the possibility of concomitant FM in patients with PsA.