High frequency of fibromyalgia in patients with psoriatic arthritis: a pilot study

Background. Widespread pain from fibromyalgia syndrome (FMS) is observed in patients with psoriatic arthritis (PsA). We hypothesized that there is increased frequency of FMS in patients with PsA that contributes to fatigue and pain. Method. We prospectively enrolled patients with PsA based on the Classification criteria for Psoriatic Arthritis and healthy subjects were used as controls. The frequency of FMS was determined using London Fibromyalgia Epidemiologic Study Screening Questionnaire (LFESSQ) and Symptoms Intensity scale (SIs). Results. 34 PsA patients and 44 controls fulfilled the inclusion criteria. Median age of PsA patients was 52 years with 53.33% females. Median age of controls was 50.5 years with 59% females. FMS was present in 53.33% of PsA patients compared to 4.54% of the controls (P < 0.001), based on LFESSQ. 37.50% of PsA had FMS compared to 6.66% of controls (P < 0.001) based on SIs. There was a significant correlation between LFESSQ and SIs in the psoriatic group (P = 0.00243). 76.66% of PsA patients complained of fatigue compared to 40.90% of controls, but the mean fatigue score between the two groups was comparable (5.03 versus 5.18). Conclusion. FMS-associated pain and fatigue are significantly more frequent in patients with PsA compared to controls.