Neuropathic pain in rheumatoid arthritis: prevalence and associated factors

This study aimed to assess the prevalence of neuropathic pain in rheumatoid arthritis (RA) patients, and to identify associated factors.

We conducted a cross-sectional study in patients with RA. Neuropathic pain was evaluated using the DN4 (Douleur Neuropathique 4) and PainDETECT scores. Agreement between the 2 questionnaires was estimated through Cohen's k. Factors associated with neuropathic pain were assessed.

A total of 121 patients with RA were included, with a mean age of 57 ±12.2 years, and a predominance of women (83%). The mean duration of RA was 16 ±1.0 years. The mean Disease Activity Score in 28 joints (DAS28) was 4.28 ±1.0, indicating moderate activity of the RA. According to the DN4 score, 61.2% of patients had neuropathic pain, and according to the PainDETECT score, 47.1% of patients were identified as having possible or likely neuropathic pain. Eighty-four patients (69.4%) had a positive DN4 score and/or a positive PainDETECT score. The coefficient of agreement k between the 2 tests was 0.233, indicating a fair agreement. Factors significantly associated with the presence of neuropathic pain were: female sex (p = 0.01), prolonged morning stiffness duration (p = 0.01), number of painful joints (p = 0.01), and number of swollen joints (p = 0.03). Additionally, the use of glucocorticosteroids (p = 0.001), analgesics (p = 0.03) and anti-CD20 drugs (p = 0.03) were significantly associated with neuropathic.

Our study suggests a potentially high prevalence of neuropathic pain in patients with RA, highlighting the need for early detection and appropriate management.