Reflex Sympathetic Dystrophy

Also known as: Complex Regional Pain syndrome; Localised Pain syndrome

Background

Reflex sympathetic dystrophy (RSD) is a chronic pain condition that is often localised to one area of the body. Somewhat confusingly it is also known as complex regional pain syndrome (CRPS) and, more generally, as localised pain syndrome (LIPs).

Pain sensitivity varies substantially among humans. A significant part of the human population develops chronic pain conditions that are characterised by heightened pain sensitivity.

Credits

Medical text written July 2007 by Dr Jacqui Clinch, Consultant in Paediatric Rheumatology and Adolescent Chronic Pain, Bristol Children’s Hospital/Royal National Hospital for Rheumatic Diseases, UK.

What are the symptoms?

It is not unusual for the pains to start in a localised area of the body (such as the ankle following sporting injury). The pains quickly intensify and there is a reluctance to move round. Often the painful area expands, spreading over time to involve larger areas of the body. In describing the pain, words such as ‘stabbing’, ‘throbbing’, ‘burning’ or ‘aching’ are used. The discomfort increases and becomes constant. As the pains continue, the young person tries not to use the area of body affected, this leads to muscular spasms, odd positioning or style of walking (gait) and greatly reduced fitness. This in turn further amplifies the pain. Unfortunately pain has a direct affect on other systems, leading to symptoms that can be as disabling as the pain itself (these include blurred vision, nausea, dizziness, headaches, extreme coldness, tummy pains and areas of numbness). Localised idiopathic pain syndrome simply describes pain that remains in a localised area (such as a limb). Within this descriptive diagnostic group are the complex regional pain syndromes (reflex sympathetic dystrophy).

What are the causes?

As with other chronic pain conditions CRPS is widely believed to be multifactoral in origin some of the factors which may contribute to the cause of the condition are:

Trauma
It is not unusual for an adolescent with a localised chronic pain to recall a sporting injury, operation or other trauma around the time that the chronic pain commenced. Whether or not this is causal is not clear. Excessive joint movement (hypermobility) has also been associated with falls and subsequent pain problems. There may often be a period of enforced immobilisation; this may be an additional factor in the development of a chronic pain syndrome.

Psychosocial factors
Although often tempting to cite psychosocial distress as a trigger to chronic pain in adolescents, the data is lacking. Undoubtedly the pain associated disability and impact on lifestyle that follows has an enormous effect on psychosocial wellbeing.

Genetics
There is some evidence that CRPS may have a genetic predisposition in Caucasian women, but the underlying genomics are far from clear. Most young people with CRPS have no other relative with the same condition.

Environmental
It has been reported that girls have lower pain thresholds, poor sleep patterns and a tendency to hypermobility when compared with boys. This may, in part, explain the greater number of females with pain conditions. With CRPS there is a small, but significant, number of boys who present.

Pathophysiological
Once more there is very little data on how body functions are related to the condition (pathophysiology) of childhood chronic pain. It has been widely postulated that, in childhood CRPS, there is either overactivity of the sympathetic nervous system or under-responsiveness of the alphaadrenergic pathways. This is unproven.

How is it diagnosed?

The diagnosis of CRPS 1 remains based on observation of symptoms (clinical). There is often a precipitating trauma but not always. The pain is usually out of proportion to the inciting event. Autonomic changes are present; these include swelling, reduced skin perfusion and difficulty in distinguishing between hot and cold. There is also a marked reduction in range of movement and, in severe cases, ulceration. In adolescents the legs are more commonly affected. Occasionally more than one limb may be affected at presentation. It is not unusual for a hand or other leg to develop CRPS months after a leg has been affected. This may be due to the use of crutches and subsequent pain amplification but may also have no obvious trigger. Young people with CRPS may also develop low mood and overwhelming fatigue. This further complicates the clinical picture.

How is it treated?

One of the most important aspects of rehabilitation is that of inclusion. A dedicated team that works consistently with the adolescent and family will facilitate communication and enable goals to be reached earlier. It is essential that the young person is worked up medically to ensure no ongoing disease process or trauma is present. If the pain is coexisting with a known illness, then it is important that this is as stable as possible before rehabilitation.

Medical therapies
The number of analgesics and interventions used is a sign that there are no well controlled therapeutic trials in the arena of childhood chronic pain. It is becoming widely accepted, however, that any analgesic intervention should be alongside multidisciplinary therapy. It is unusual for analgesia to work alone.

Complementary therapies are commonly utilised by patients with chronic pain. The evidence supporting many of these therapies in children and adolescents is poor but many young adults find certain therapies such as acupuncture, massage and aromatherapy helpful.

Multidisciplinary rehabilitation
The aim of treatment is to enable the young person to return to age appropriate activities and lifestyle. Ideally this would be pain free but, in many cases, this is initially with the pain.

Physiotherapists, occupational therapists and psychologists are key players in the team. They will be the primary professionals supporting the young person and the family. The physician is there to provide support if needed, occasional analgesic advice and very rarely, direct intervention. Intensive physiotherapy may be given for a set period of time. The aim of this is accelerated mobilisation. However many cases of pain will require a gentle, paced approach. In all cases the increase of activity should be consistent despite the pain. Where possible the young person should work to devise their own ‘fitness plan’. Fun games can be included with an aim to return gradually to activities the young person previously enjoyed. Using a local gym rather than a hospital physiotherapy gym allows them to start to return to a more normal environment.

Working in this consistent, paced manner is extremely hard for the young person and their parents. The pain invariably continues at the beginning (if not throughout) and motivation is poor. Parental anxiety is understandably high and there is a fear that damage will be done. Psychological support during this time is key. The young person will need help setting goals, learning how to communicate pain to peers and family, keeping up motivation on ‘bad days’, managing low mood, dealing with anger and frustration and overcoming fears. Often they have not been at school for a long period of time and need help in preparing again for this difficult environment. In some cases there may be other mental health needs that can be identified and appropriately treated. Relaxation, advice on sleep and eating and advice on how to pace other areas of life can all be given by members of the team.

Most cases of complex regional pain syndromes in children have a favourable prognosis if early physiotherapy is initiated (with psychological support). A prolonged time to treatment and the presence of marked autonomic changes are not good prognostic indicators. Relapses of pain are relatively common but, in our experience, if the young person and their family recognise the onset of similar pains and put into practice physical and emotional strategies that have previously been taught, then the impact of the pains can be significantly reduced.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
As far as we can ascertain, inherited predisposition to this syndrome is unclear.

Prenatal diagnosis
None.

Is there support?

There is no support group for reflex sympathetic dystrophy in the UK.

Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. To meet other families with disabled children, join Contact’s closed (private) Facebook group.

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