Reflex sympathetic dystrophy in adolescents: lessons for adults.

Persistent pain without clear explanation frequently involves the musculoskeletal system, with the core clinical features being the presence of pain and abnormal tenderness in the same area. Such conditions may be widespread or localized, that is, to an upper or lower quadrant or, less commonly, to a more restricted distal limb region. The causes, pathophysiologic mechanisms, clinical presentations, and management strategies of these chronic pain syndromes remain controversial (1). Any insight into any aspect of these problems is welcomed. It is often difficult for a clinician to know where to begin when assessing such patients. There may be a number of possible causes, differing severity of clinical features, and marked variation in response to treatments. Outcomes also differ greatly. It is no wonder that with such multidimensional disorders any commentator on the topic is inevitably partly right and partly wrong! Psychological and social factors provide input into the mechanisms of disordered pain biology but are also major consequences of this process. As such, the biopsychosocial model of disease is usefully applied to these disorders (2,3). Both the common fibromyalgia syndrome and less common complex regional pain syndrome (CRPS), also known as reflex sympathetic dystrophy (RSD), are better managed with this approach. As in other pain syndromes, the study of CRPS/RSD has been associated with refinement of terminology and classification criteria (4). For many years, terms such as algodystrophy and Sudeck’s atrophy have emphasized the uncommon outcome of severe tissue damage, whereas the popular term reflex sympathetic dystrophy incorporates the putative role of the sympathetic nervous system in this disorder. More recently, the descriptive term complex regional pain syndrome has gained favor to emphasize the clinical features without implication of causative mechanisms (5), somewhat akin to the reasons for use of the term fibromyalgia syndrome (6). Parallel to taxonomic changes, criteria to classify and diagnose CRPS continue to evolve (7,8). In classic CRPS, the clinical features are usually obvious and often spectacular. Indeed, orthopedic surgeons may make this clinical diagnosis! Seeing is believing—swelling, vascular change, and marked tenderness all may be prominent. However, CRPS exists on a spectrum with milder CRPS being far more common than the severe types that characterize textbook descriptions. In many cases, clinical features may be more subtle, particularly initially. Many of these issues are highlighted in the article by Maillard et al (8) in this issue of Arthritis Care & Research, in which 23 adolescent patients with CRPS, who attended a single pediatric unit at a London hospital, are reviewed. Despite the limitations of the methodology involved in this retrospective review, the described clinical approach to CRPS is very sensible and contributes further understanding to an important and often underreported condition. The observations in these adolescents carry important lessons for those managing CRPS in adult patients. First, the review highlights the difficulty of diagnosing CRPS. This difficulty arises because there is often a low level of awareness of the condition among the various health professionals who are confronted by persons with persisting regional pain problems. However, it also relates to the overlap between early clinical features of CRPS and those that associate with the normal and expected temporary process of postinjury pain sensitization. In such settings, CRPS may simply “creep up on you. ” What, then, might alert a health care professional to a person being a candidate to develop CRPS? One important clue is the presence of a specific trigger, such as tissue injury, that occurs in a highly charged emotional context. Examples range from myocardial infarction to arthroscopy. Here, psychosocial distress may associate with either pain out of proportion to the underlying tissue damage or persisting beyond the normal time of tissue healing. In such situations, the astute clinician will usually anticipate a possible pain syndrome well before any specific criteria are met. In this setting preventive strategies, such as explanation, moGeoffrey O. Littlejohn, MD, MPH, MBBS (Hons), FRACP: Clayton, Melbourne, Australia. Address correspondence to Geoffrey O. Littlejohn, MD, MPH, MBBS (Hons), FRACP Associate Professor of Rheumatology, Monash University/Monash Medical Centre, 246 Clayton Road, Clayton, Melbourne, Australia. E-mail: geoff.littlejohn@med.monash. edu.au. Submitted for publication November 5, 2003; accepted November 10, 2003. Arthritis & Rheumatism (Arthritis Care & Research) Vol. 51, No. 2, April 15, 2004, pp 151–153 DOI 10.1002/art.20250 © 2004, American College of Rheumatology