Complex regional pain syndromeBMJ 2014; 348 doi: https://doi.org/10.1136/bmj.g3683 (Published 25 June 2014) Cite this as: BMJ 2014;348:g3683
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(Author's Reply) Do we really know all that we think we know about the epidemiology and management of Complex Regional Pain Cyndrome?
We are grateful for the comment of Notcutt on our article on Complex Regional Pain Syndrome (CRPS). We also believe that prompt referral of patients suffering from CRPS to specialty Pain Clinics is essential. In fact this is a belief shared by most specialists in Pain Medicine and that is reaffirmed by available guidelines on the management of CRPS [1–3]. However, when searching the literature to write that article we were alarmed by the lack of good quality evidence supporting that belief. On the one hand it would be absurd to design a clinical trial where patients suffering from CRPS would be randomized for early or late referral for a specialty Pain Clinic. On the other hand current knowledge on the epidemiology of CRPS is so limited that our belief could stem from selection bias, as specialists in Pain Medicine tend to see patients with most severe signs and symptoms whereas patients with milder forms of CRPS could experience early resolution. For instance, contrary to usual belief Sandroni et al showed in their retrospective population-based study on CRPS that 55 of 74 patients with a diagnosis of CRPS had experienced complete pain resolution and did not require further drug treatment for pain .
We concur that good judgment requires that, given the possibility of severe outcomes (refractory pain and disability), most patients with anything but mild symptoms of CRPS should be promptly referred to specialty Pain Clinics. However, the same good judgement tells us that General Practitioners can play an important role in the co-management of patients with CRPS beyond that of suspecting the diagnosis and making referrals to Pain Clinics. For instance, GPs can start patients on medications used for the treatment of neuropathic pain and provide guidance to patients on behavioural strategies to cope with chronic pain in order to decrease symptoms and disability.
Another common belief of Pain specialist about CRPS for which we found it particularly difficult to find supporting evidence, concerns the frequency of underdiagnosis and/or late diagnosis of CRPS. Pain specialists are used to seeing patients who were correctly diagnosed with CRPS only after several months of constant severe pain and disability. However the reference cited by most reviews as providing evidence of late or underdiagnosis was a study of retrospective chart review that reported only the mean duration of symptoms and the mean number of different physicians patients had seen prior to their assessment at the pain clinic under study, without any data about when the diagnosis of CRPS was made or when patients were referred to that or any other Pain clinic . Furthermore, contrary to current belief, a recent – and strongly criticized – Personal View article published in The BMJ argued that CRPS was being overdiagnosed by “inexperienced junior doctors when confronted by patients with unexplained symptoms, especially pain in the hands and feet” .
Putting in doubt what we think we know for certain is one important way to devise new research strategies and to find new answers.
1. Goebel A, Barker CH, Turner-Stokes L, et al. Complex regional pain syndrome in adults: UK guidelines for diagnosis, referral and management in primary and secondary care. London: : RCP 2012. http://www.rcplondon.ac.uk/resources/complex-regional-pain-syndrome-guid... (accessed 31 Jan2013).
2. Perez RS, Zollinger PE, Dijkstra PU, et al. Evidence based guidelines for complex regional pain syndrome type 1. BMC Neurol 2010;10:20. doi:10.1186/1471-2377-10-20
3. Harden RN, Oaklander AL, Burton AW, et al. Complex regional pain syndrome: practical diagnostic and treatment guidelines, 4th edition. Pain Med Malden Mass 2013;14:180–229. doi:10.1111/pme.12033
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;103:199–207.
5. Bass C. Complex regional pain syndrome medicalises limb pain. BMJ 2014;348:g2631–g2631. doi:10.1136/bmj.g2631
6. Allen G, Galer BS, Schwartz L. Epidemiology of complex regional pain syndrome: a retrospective chart review of 134 patients. Pain 1999;80:539–44.
Competing interests: No competing interests
Perhaps the most important message from this article concerns the prompt referral to Pain Management services for effective pain management alongside high quality physiotherapy to restore mobility. This means that such patients are treated urgently and not stuck on a 6 month waiting list. It also means that Orthopaedic surgeons and others must recognise the early signs and act on them.
For many years we have had this approach in our hospital and florid examples of CRPS are rare. Sadly we haven't collected the data. However, I would rather see 10 patients in the early stages and treat them effectively, than 1 patient with a neglected, dystrophic and allodynic limb that is barely salvageable, and a patient asking for amputation.
CRPS is difficult to treat when well established. Therefore prevention by early management is critical.
Competing interests: No competing interests