Complex regional pain syndrome evolution is determined by both biological and psychosocial factors: a 1-year prospective observational study.

Complex regional pain syndrome (CRPS) is a challenging condition with unpredictable clinical evolution. Identifying early prognostic factors could transform patient management and improve outcomes. This prospective study followed 113 patients with early CRPS (<6 months) over 1 year to assess clinical evolution and investigate key predictors of chronification. Participants underwent repeated clinical assessments, quantitative sensory testing, and self-reported evaluations at 4 time points over 1 year. Multivariable mixed-effect models were used to identify independent early prognostic factors. Despite some improvement, 35% of the participants still met Budapest criteria at 1 year, with persistent pain, disability, and impaired quality of life. Sensory profiles appeared to stabilize after a few months, while body perception disturbance scores did not change during the follow-up period. Psychosocial factors, such as baseline disability, psychosocial severity, and social support, as well as body mass index and allodynia, were predictors of long-term outcomes. Biopsychosocial Early CRPS profiles defined through a latent class analysis carried out on the basis of data measured at inclusion revealed distinct clinical trajectories and showed stronger prognostic value than previously suggested CRPS classifications (eg, based on skin temperature). These findings highlight the importance of an early assessment incorporating biopsychosocial elements to stratify risk and tailor interventions. Our study paves the way for the development of a clinical tool to predict CRPS evolution, potentially enabling tailored treatments. Future research should validate these predictive models and explore their integration into routine practice, potentially improving the management of early CRPS.