Clinical phenotyping of youth with new-onset musculoskeletal pain a controlled cohort study

Objectives: The course of pediatric musculoskeletal pain from acute to chronic has not been well described and there is limited understanding of how to identify individuals with new-onset pain who may be predisposed to developing persisting symptoms. Thus, the purpose of this study was to describe the clinical phonotype of treatment-seeking youth with new-onset musculoskeletal pain compared with youth with and without chronic pain. Further, we tested predictors of pain-related disability and pain sensitivity in the new-onset pain sample. Methods: Participants were 191 youth, ages 10 to 17 years, representing 3 cohorts (new-onset musculoskeletal pain, chronic musculoskeletal pain, and a comparison group without chronic pain). Participants completed questionnaire measures of pain characteristics, psychological functioning, sleep, and pain-related disability. They also attended a laboratory visit to complete an experimental pain assessment using heat and cold stimuli to assess pain sensitivity and conditioned pain modulation. Results: Findings revealed youth with new-onset musculoskeletal pain had a distinct clinical phenotype where symptoms of pain and disability were in the mid-range between those of youth with diagnosed chronic musculoskeletal pain and youth in the community without chronic pain. Linear regressions within the newonset pain sample demonstrated poorer sleep quality and higher pain fear predicted greater pain-related disability, and pain catastrophizing predicted cold pressor sensitivity. Discussion: Clinical phenotyping of youth with new-onset musculoskeletal pain highlights factors relevant to the pain experience. Future research can examine the roles of these variables in predicting longitudinal risk for chronic pain and disability.