Clin J Pain. 2009;25:273-280

The Natural History of Complex Regional Pain Syndrome
Robert J. Schwartzman, MD, Kirsten L. Erwin, BS, and Guillermo M. Alexander, PhD

Objective: Complex regional pain syndrome (CRPS) is a severe
chronic pain condition characterized by sensory, autonomic,
motor, and dystrophic signs and symptoms. This study was
undertaken to expand our current knowledge of the evolution of
CRPS signs and symptoms with duration of disease.

Method: This was a retrospective, cross-sectional analysis using
data extracted from a patient questionnaire to evaluate the clinical
characteristics of CRPS at different time points of disease
progression. Data from the questionnaire included pain characteristics
and associated symptoms. It also included autonomic, motor,
and dystrophic symptoms and also initiating events, ameliorating
and aggravating factors, quality of life, work status, comorbid
conditions, pattern of pain spread, family history, and demographics.
Comparisons were made of different parameters as they
varied with disease duration.

Results: A total of 656 patients with CRPS of at least 1-year
duration were evaluated. The average age of all participants was
37.5 years, with disease duration varying from 1 to 46 years. The
majority of participants were white (96%). A total of 80.3% were
females. None of the patients in this study demonstrated
spontaneous remission of their symptoms. The pain in these
patients was refractory showing only modest improvement with
most current therapies.

Discussion: This study shows that although CRPS is a progressive
disease, after 1 year, the majority of the signs and symptoms were
well developed and although many variables worsen over the
course of the illness, the majority demonstrated only moderate
increases with disease duration.