# Effectiveness of Decision Support to Treat Complex Regional Pain Syndrome
## 1 Introduction  
Complex regional pain syndrome (CRPS) type 1, or algodystrophy, is a painful and disabling condition that usually manifests in response to trauma or surgery [1,2]. CRPS type 1 is a frequent disorder usually involving distal extremities such as the wrist, hand, ankle, and foot. It is characterized by a complex set of symptoms where no correlation can be identified between the symptoms reported by patients and the putative cause [3]. Severe pain is the most common feature of CRPS, together with a various array of accompanying symptoms ranging from cutaneous dyschromia to altered cutaneous temperature, severe edema, hyperesthesia/allodynia, regional osteoporosis, reduced range of motion (ROM), and trophic changes [3, 4, 5, 6]. According to the International Association for the Study of Pain criteria, the characteristic features required to establish CRPS type 1 diagnosis are: (i) the presence of an initiating noxious event or a cause of immobilization; (ii) continuing pain, allodynia, orhyperalgesia with pain disproportionate to any inciting event; (iii) evidence at some time of edema, changes in skin blood flow, or abnormal sdomotor activity in the region of the pain; and (iv) the exclusion of medical conditions that would otherwise account for the degree of pain and dysfunction [7]. Motor disturbances and trophic changes, such as altered nail and hair growth, may be observed in some cases. Beyond CRPS type 1, which occurs without preceding nerve injury, CRPS type 2 has the same clinical features as type 1, except for the presence of clinical signs and history consistent with a nerve injury [8]. Given its different clinical manifestations, CRPS has been divided by many authors into three distinct phases, which are not necessarily progressive, in relation to the time elapsed from the manifestation of signs and symptoms to diagnosis. Stage I (0-3 months), or the inflammatory, acute phase, is characterized by severe, deep pain coming from deep tissues such as muscles and bones, which is exacerbated by direct contact and a declined position [3; 9]. Hypesthesia or allodynia are usually reported by patients, and the skin is red, warm, and oedemaous. Hand ROM is also restricted as a consequence of pain during its mobilization. Stage II (3-6 months), or the dystrophic phase, is characterized by pain reduction, edema organization, and increased articular stiffness. The skin turns cold, cyanotic, and exudative with trophic change to the nails [3; 9]. Stage III (6-9 months), or the atrophic phase, is usually prevented by prompt diagnosis and treatment. It is characterized by fluctuating pain, and the skin appears smooth, having lost its skin folds, with a yearly appearance and decreased temperature. Subcutaneous as well as muscular tissues are atrophic, and severe articular contractures are usually present with an important reduction in the normal ROM and palmar fibrosis [3; 9]. In recent years, some European countries have developed their own guidelines for the management of CRPS patients [10; 11; 12; 13]. To date, there is no gold standard for CRPS management, a multidisciplinary and integrated approach would be optimal. Both the Dutch (2006) [14] and English (2012) [15] guidelines, as well as the Cochrane systematic review of 2016 [6], highlight how a multidisciplinary approach is of pivot to evaluate and treat, as best as possible, every single aspect of CRPS and how setting up an early rehabilitation intervention is fundamental to have the most favorable prognosis. Unfortunately, as explained by [PERSON] and colleagues [16], great difficulty persists in recognizing both the signs and symptoms (Budapest criteria) as well as in making a correct and early diagnosis by all health professionals. Within this frame, rehabilitative therapies remain the mainstay of CRPS management. It is well recognized that an early rehabilitation program performed by specialized hand therapists plays a paramount role in the timely and accurate management of these patients within a multidisciplinary team approach.