Neuropathic Pain in Hand Osteoarthritis: A Cross-Sectional Study
Symptomatic hand osteoarthritis (OA) is a severely debilitating condition. Neuropathic pain (NP) has been shown to be a factor affecting pain severity, hand function, psychological wellbeing, body schema, and the number of pain medications in people with OA of other joints. The aim of this study was to assess the prevalence of NP in symptomatic hand OA and assess its association with pain, hand function, measures of psychological wellbeing, sleep, body schema disturbances, and number of pain medications. Participants with symptomatic hand OA diagnosed through the American College of Rheumatology criteria, were recruited and completed a series of online questionnaires. These included the Douleur Neuropathique 4 interview (DN4-interview), Short Form Brief Pain Inventory (SF-BPI), Neglect-like Symptoms questionnaire, Functional Index of Hand Osteoarthritis (FIHOA), Centre for Epidemiologic Studies Depression Scale (CES-D), Pain Catastrophising Scale (PCS), and the Pittsburgh Sleep Quality Index (PSQI). Logistic regression with age, body mass index, and sex as covariates were utilised to assess differences between participants with and without NP as identified through the DN4-interview. Correlation analysis assessed the relationship between pain intensity, body schema alterations, and number of pain medications. A total of 121 participants were included in the present study. Forty-two percent of participants presented with NP. Participants with NP reported higher levels of worst pain (OR: 10.2 95% CI: 2.2 to 48.5; p = 0.007). Worst pain intensity correlated with the number of pain medications (rho = 0.2; p = 0.04), and neglect-like symptoms (rho = 0.4; p < 0.0001). No difference between phenotypes was shown for catastrophising, function, depression, neglect-like symptoms, pain interference, or sleep. A large proportion of people with symptomatic hand OA present with NP. This phenotype is characterised by greater levels of pain intensity. Pain intensity is associated with number of pain relief medications and body schema alteration. Psychological factors, hand function, and sleep do not appear to be affected by the presence of NP.