A pain syndrome with many names
The first descriptions of CRPS were made at the end of the 19th century. Over time, various synonymous terms were used:
- Sudeck's disease
- Reflex dystrophy
- Algodystrophy
- Sympathetic reflex dystrophy
These terms were increasingly replaced by the internationally standardized term Complex Regional Pain Syndrome (CRPS).
Symptoms
Main symptom: pain
The main symptom of CRPS is pain. Patients often describe a combination of burning, stabbing and tingling pain.
Hypersensitivity
The skin of the affected limb can be extremely sensitive. Light touches that are not normally painful or changes in the ambient temperature can trigger intense pain.
The following medical terms are important in this context:
- Hyperalgesia - Local external pressure or a temperature influence that is not normally perceived as painful clearly triggers pain.
- Allodynia - A touch that is not normally painful (e.g. stroking the skin) triggers an unpleasant pain reaction.
Sudden swelling, unexpected temperature changes
Affected areas of the body can swell again and again. Joints that are also affected are often stiff and mobility is restricted. The skin may appear overheated, red and dry, but later it may also be cold, bluish and sweaty.
Changes in hair and nail growth
In limbs affected by CRPS, hair and nail growth may be unusually slow or rapid.
Strange sensations
Strange sensations may occur in the limb affected by CRPS. It may feel as if it does not belong to the body. Compared to the healthy opposite side, an affected limb may feel smaller or larger.
Stress can make CRPS worse
Stress can lead to a temporary increase in CRPS symptoms. These “flare-ups” make the pain situation worse and can last for days to weeks before improving again.
Causes
CRPS usually develops as a result of an injury. Symptoms typically appear within weeks of the injury. Injuries associated with CRPS can include broken bones, cuts, surgical interventions, burns or simply a sprain.
The exact causes or mechanisms of CRPS are unknown. Due to the complex nature of the symptoms, it seems unlikely that this disease has a single, simple cause.
One of the main theories is based on the assumption that CRPS is the result of an abnormal, extended reaction of the body to an injury. It is assumed that various systems in the body can malfunction and together contribute to CRPS:
- Brain and spinal cord
- Peripheral nerves (=nerves outside the brain and spinal cord)
- Immune system
- Blood vessels (arteries and veins)
Diagnosis
Diagnosing CRPS is difficult. There is no suitable test that allows an unequivocal diagnosis. CRPS is usually diagnosed by excluding other diseases that have similar symptoms.
If chronic pain in a limb cannot be adequately explained by a medical examination, targeted blood tests and radiological methods (e.g. MRI, X-ray, scintigraphy), CRPS is conceivable.
The diagnosis is ultimately made according to the criteria of the IASP (International Association for the Study of Pain), which were drawn up in Budapest in 2003 and are therefore also known as the "Budapest criteria".
Therapeutic options
In order to prevent further chronification and to support a cure, treatment of CRPS should be started as early as possible.
Treatment of CRPS almost always involves a combination of different therapeutic measures. The therapeutic goals should not only be aimed at reducing the pain problem, but also at improving or maintaining the function of the limb in question (e.g. foot: walking, hand: grasping).
Suitable therapy for CRPS must be individually tailored to the affected patient. As a rule, non-medicinal, medicinal and, if necessary, interventional measures are combined.
Prognosis
It is estimated that approximately 85% of patients affected by CRPS experience a noticeable improvement in their symptoms within two years.
