The Neuropathic Pain Features in Psoriatic Arthritis: A Cross-sectional Evaluation of Prevalence and Associated Factors

Objective. To evaluate the prevalence and factors associated with the neuropathic pain features in a cohort of patients with psoriatic arthritis (PsA). Methods. A cross-sectional evaluation was conducted in consecutive patients having PsA with prevalent peripheral joint involvement, referred to 3 rheumatological centers. For each patient, a comprehensive assessment of disease activity, physical function, and disease effect was carried out. The presence of comorbid fibromyalgia syndrome (FMS) was evaluated. Acute-phase reactants were also recorded. The neuropathic pain features were investigated through the PainDETECT Questionnaire (PDQ). A logistic regression analysis was therefore conducted using the PDQ as the dependent variable. Results. The final evaluation included 118 patients. A comorbid FMS was detectable in 30 of the 118 patients with PsA (25.4%). Probable characteristics of neuropathic pain (PDQ >= 19) were found in 30 (25.4%) patients overall, ambiguous (PDQ > 12 and < 19) in 21 (17.8%) patients, and unlikely (PDQ <= 12) in 67 (56.8%) patients. Using logistic regression analysis, the only independent variable among those investigated that could explain the neuropathic pain features was the presence of a comorbid FMS (p = 0.0127). Excluding patients with comorbid FMS, an association with disability (measured by Health Assessment Questionnaire-Disability Index) emerges (p = 0.0489). In patients with PsA and comorbid FMS, PDQ scores were significantly higher than in patients without comorbid FMS. Conclusion. Neuropathic pain features are common in patients with PsA, and the presence of pain sensitization (comorbid FMS) seems to be its main predictor.