CRPS can be divided into acute and chronic forms, with a reasonably good prognosis in the first year, but a poorer prognosis thereafter.[115]de Mos M, Huygen FJ, van der Hoeven-Borgman M, et al. Outcome of the complex regional pain syndrome. Clin J Pain. 2009 Sep;25(7):590-7.
http://www.ncbi.nlm.nih.gov/pubmed/19692800?tool=bestpractice.com
[116]Schwartzman RJ, Erwin KL, Alexander GM. The natural history of complex regional pain syndrome. Clin J Pain. 2009 May;25(4):273-80.
http://www.ncbi.nlm.nih.gov/pubmed/19590474?tool=bestpractice.com
In a population-based study, type 1 CRPS resolved in 74% of patients, most within the first year, including many who received no specific intervention.[4]Sandroni P, Benrud-Larson LM, McClelland RL, et al. Complex regional pain syndrome type I: incidence and prevalence in Olmsted county, a population-based study. Pain. 2003 May;103(1-2):199-207.
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This suggests that spontaneous resolution may be more common than previously thought. Outcome was not associated with age, sex, or affected site, but the best resolution rate was associated with occurrence following fractures (91%).[4]Sandroni P, Benrud-Larson LM, McClelland RL, et al. Complex regional pain syndrome type I: incidence and prevalence in Olmsted county, a population-based study. Pain. 2003 May;103(1-2):199-207.
http://www.ncbi.nlm.nih.gov/pubmed/12749974?tool=bestpractice.com
One review concluded that, for patients with long-lasting type 1 CRPS, there is insufficient evidence to draw conclusions regarding prognosis.[117]Wertli M, Bachmann LM, Weiner SS, et al. Prognostic factors in complex regional pain syndrome 1: a systematic review. J Rehabil Med. 2013 Mar;45(3):225-31.
https://www.medicaljournals.se/jrm/content/html/10.2340/16501977-1103
http://www.ncbi.nlm.nih.gov/pubmed/23389624?tool=bestpractice.com
Subsequent reviews of CRPS suggest that prognosis is not as poor as commonly assumed.[51]Birklein F, O’Neill D, Schlereth T. Complex regional pain syndrome: an optimistic perspective. Neurology. 2015 Jan 6;84(1):89-96.
http://www.ncbi.nlm.nih.gov/pubmed/25471395?tool=bestpractice.com
[118]Gierthmühlen J, Binder A, Baron R. Mechanism-based treatment in complex regional pain syndromes. Nat Rev Neurol. 2014 Sep;10(9):518-28.
http://www.ncbi.nlm.nih.gov/pubmed/25134708?tool=bestpractice.com