Musculoskeletal Pain and Neuropathic Pain Features Among Individuals with Long COVID and a History of Pain: Characteristics and Impact on Health-Related Quality of Life

Background: Post-COVID-19 syndrome or Long COVID (LC) is a multi-system condition characterised by persistent symptoms beyond three months following SARS-CoV-2 infection. Pain, particularly musculoskeletal and neuropathic pain, is commonly reported and may substantially affect functioning and health-related quality of life (HRQoL). However, there is limited detailed characterisation of pain phenotypes and their differential impact on outcomes in LC. This study aimed to (i) characterise pain associated with LC, (ii) identify factors associated with pain type and severity, and (iii) examine its impact on HRQoL, physical activity, and work. Methods: A cross-sectional survey was conducted among adults with clinician-diagnosed or self-reported LC who reported current or previous joint, muscle, or nerve pain. Participants completed validated patient-reported outcome measures including the C19-YRS, Nordic Musculoskeletal Questionnaire, Pain Detect Questionnaire (PD-Q), Musculoskeletal Health Questionnaire, and EQ-5D-5L. Participants were classified into neuropathic, nociceptive, or ambiguous pain groups based on PD-Q scores. Descriptive analyses, group comparisons, and backward stepwise ordinary least squares regression were used to examine factors associated with overall pain (PD-Q Total). Results: Among 198 participants (73% female; mean age 52 ± 12.7 years; mean LC duration 2.4 years), 96% reported new or worsened pain following COVID-19 infection, with muscle pain (87%), joint pain (84%), and nerve pain (66%) most frequently reported. PD-Q scores suggestive of neuropathic pain were identified in 28% of participants and were associated with significantly greater pain intensity, symptom burden, functional impairment, and lower HRQoL (p < 0.05). These participants reported higher average pain scores across all body regions and greater radiating pain (76%) compared to other groups. Functional disability and anxiety were significant factors associated with pain severity. Conclusions: Pain is highly prevalent in LC, with neuropathic pain representing a distinct and more severe phenotype associated with substantial functional and quality-of-life impacts. This study provides novel comparative evidence on pain phenotypes and their differential burden, highlighting the need for targeted pain assessment and management strategies in LC.