Complex regional pain syndrome: a long overlooked condition

Complex regional pain syndrome (CRPS) is a debilitating condition that affects the limbs and can be induced by trauma or surgery. An article recently published in Burns & Trauma provides a comprehensive summary of this little known condition and gives an update on recent progress in treatment.

CRPS image full
CRPS sufferer
Fernanda B Fukushima et al. BMJ 2014;348:bmj.g3683

Complex regional pain syndrome (CRPS) is a debilitating condition that has been studied since it was first described by Weir Mitchell in the 1860s. During the civil war, he had keenly observed a pattern of clinical signs and symptoms with much consistency, and termed it, rather innovatively, causalgia.

This is a condition, which we had come across in our formative years in medical school, but only recently did we see patients with this condition. Often, physicians found it difficult to characterize, which led to a late diagnosis. Furthermore, explaining to patients about the diagnosis proved equally challenging. In both instances, the ever-changing terminology and nosology of CRPS played a huge role.

Due to the multi- factorial nature of this condition, animal models that can simulate the disease process are lacking.

Over the years, the complex nature of CRPS has proved an enormous challenge for clinicians and researchers alike. Since the turn of the millennium, only two randomized, placebo-controlled trials have been conducted in the United States, both of which have demonstrated disappointing results. Due to the multi- factorial nature of this condition, animal models that can simulate the disease process are lacking, which is further compounded by our limited understanding of the mechanisms involved.

This has hindered the development of new therapies, leading clinicians to adopt a trial and error approach towards managing this syndrome. Hence, most studies evaluating novel approaches have been restricted to case series or small pilot studies. The recent declaration by the United States Food and Drug Administration of CRPS as an official disease has given us renewed hope, as this has been a catalyst for new drug development.

Recently, an article entitled “Complex Regional Pain Syndrome: A Recent Update” was published in Burns & Trauma, which provides a comprehensive summary of the latest developments in our understanding of CRPS. CRPS is now classified as Type I, which occurs due to noxious event in a disproportionate way in the absence of nerve injury. Meanwhile, Type II is characterized by a burning pain with features of allodynia and hyperpathia in the presence of nerve injury. Type I is more common, and can be attributed to differences in ethnic and socio-economic background.

Over the years, physicians have managed CRPS with physiotherapy and proper diet to alleviate the symptoms. Given the chronic pain the patients experience, many often seek psychiatric appointments to cope with the pain, and avoid long-term anxiety disorders. From a preventative perspective, the use of anti-oxidants is recommended by expert opinion. From our interactions with these patients, it became more evident that handling complications is as important as managing CRPS. A good example is the onset of osteoporosis, which compounds the pain these patients already experience and complicates both the diagnosis and treatment.

Given the chronic pain the patients experience, many often seek psychiatric appointments to cope with the pain.

Unraveling the complex pathophysiology of this condition enables us to develop better treatment methods. Although there has yet to be a successful treatment for CRPS to date, years of research have provided us with many valuable lessons and our understanding of this condition continues to grow. As with any pain-related condition, the patients are very diverse, in their presentation, underlying pathophysiology as well as their response to therapies employed. Hence, future work is still required to elucidate the subgroups of patients who would benefit the most from currently available treatment.

Given the complex nature of this syndrome, it is unlikely that targeting a specific mechanism will be effective. As with other chronic disorders, the future of CRPS treatment may lie in combination therapy and studies investigating this will be necessary. We hope that this update will serve its purpose well in updating the readers of the latest work on CRPS, and enable them to make informed decisions in their clinical approach.

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