Sudeck's Disease (CRPS) – Specialists in the Diagnosis and Treatment of Complex Regional Pain Syndrome

Complex Regional Pain Syndrome, or CRPS for short, is also known as “Sudeck’s disease” or “sympathetic reflex dystrophy.” It manifests as (chronic) pain, primarily characterized by

• pain upon touch (allodynia),
• inflammation,
• reduced mobility and reduced strength, as well as
• sensory disturbances.

The condition primarily affects the hands or feet.

CRPS occurs in 2–15% of cases following injuries to the arms or legs. This risk is particularly high after

• bone fractures,
• surgeries, and
• other serious injuries.

It is less common for CRPS to develop following minor injuries, such as cuts or insect bites. Women are two to three times more likely to be affected than men. CRPS occurs primarily between the ages of 40 and 70; it is rare in children and the elderly.

The cause of CRPS remains unclear to this day. It is believed to result from a combination of

• inflammatory and neurogenic (nerve-related) processes, as well as
• changes in the brain and spinal cord.

These various processes are responsible for the wide range of symptoms. However, not every symptom occurs in every patient. Inflammation within the body is normal. It always occurs after tissue damage and is regulated by the body. In CRPS, however, this inflammatory response is more pronounced. The body can no longer control it.

However, a healing response can still begin even months or years later.

A distinction is made between CRPS I and CRPS II. In CRPS I, there is no detectable nerve lesion. In CRPS II, there is damage to the affected nerves. For treatment, however, this distinction is irrelevant. The therapies are identical.

Symptoms may change as the disease progresses. For example, central changes (affecting the spinal cord and brain) may occur later in the course of the disease.

The acute phase of the disease is characterized by excessive and prolonged inflammation. It typically lasts up to six months after the injury.

Visible symptoms include

• swelling,
• changes in skin color and temperature (warmer, colder) of the affected body part, as well as
• increased sweating or
• changes in fingernail and hair growth.

Other symptoms include impaired mobility; for example,

• inability to fully clench the fist or
• flexion and extension in the wrist or ankle may be reduced

. Strength is often reduced.

The pain may be constant or exertion-dependent. The intensity of the pain may fluctuate throughout the day. Pain may also be exacerbated by external factors such as

• heat,
• cold, or
• light touch

. However, touch may also feel numb or cause a tingling sensation like ants crawling on the skin. Some patients feel as though the affected body part is no longer part of their body. This can lead to re-injury, for example, from bumping into something.

The diagnosis of Sudeck’s disease is made clinically. Imaging procedures such as X-rays, MRI, and bone scintigraphy are not necessary. The doctor diagnoses CRPS based on specific symptoms and by ruling out other conditions.

The most important tool for diagnosis is the Budapest Criteria, which can be found in the CRPS guidelines.

Budapest Criteria

Persistent, excessive pain that can no longer be explained by the original injury.

The patient must exhibit at least one symptom from each of 3 of the following 4 categories:

1. Hypersensitivity to pain stimuli (hyperalgesia) or to touch (hyperesthesia); normally non-painful touches cause pain, e.g., with gentle touch (allodynia).
2. Altered skin temperature or skin color (pale, bluish, reddened) when comparing one side to the other (asymmetry).
3. Asymmetrical changes in sweating or swelling due to increased tissue fluid retention (edema).
4. Reduced mobility due to, for example, persistent changes in involuntary muscle tone (dystonia), involuntary rhythmic shaking (tremor), or muscle weakness (paresis). Changes in hair or nail growth.

At the time of the medical examination, the affected individual must exhibit at least one symptom from each of two of the following four categories:

1. Pain triggered by otherwise non-painful stimuli, such as gentle stroking of the skin (allodynia), or hypersensitivity to, for example, moderate, sharp stimuli such as being touched with a toothpick. Pain upon pressure on joints, bones, or muscles (hyperesthesia or hyperalgesia)
2. Asymmetrical changes in skin temperature or skin color.
3. Asymmetrical local sweating or swelling due to increased accumulation of tissue fluid (edema). 
4. Reduced mobility due to, for example, persistent changes in involuntary muscle tone (dystonia), involuntary rhythmic shaking (tremor), or muscle weakness (paresis). Changes in hair or nail growth.
5. There is no other diagnosis that fits the symptoms. Rheumatic disorders, thrombosis, compartment syndrome, etc., should be ruled out in the differential diagnosis. 

There is no cause-specific (causal) treatment for CRPS, as the cause is unknown. Treatment is therefore based on the patient’s current symptoms and the CRPS guidelines. Multimodal pain management is recommended.

Here, pain therapists collaborate with experts in occupational therapy, physical therapy, and psychotherapy. 

In the acute phase, anti-inflammatory therapy is important. Cortisone is primarily used here as long as inflammatory symptoms are still present. This treatment should not be continued for longer than 6–12 months. 

Pain management usually consists of temporary administration

• anti-inflammatory pain relievers and
• so-called co-analgesics

. These include, for example, medications for

• epileptic seizures (so-called anticonvulsants) or
• depression (so-called antidepressants), which can also have pain-relieving effects.

Surgery should only be performed at specialized centers if other therapies have proven ineffective. In cases of CRPS, any type of surgical intervention—unless life-threatening—should be carefully weighed. Such procedures can trigger a recurrence of the condition, even in a different limb. 

One of the most important components of treatment is active physical and occupational therapy. Complete immobilization should be avoided. Exercises to improve strength and mobility should also be performed at home. Active exercises may lead to a temporary increase in pain. In the long term, however, they are important for maintaining function. 

Mirror therapy is one treatment option. In CRPS, the areas of the brain that innervate the affected limb atrophy, leading to a loss of body schema. Mirror therapy tricks the brain into believing that the affected limb is moving pain-free. This stimulates the neglected region of the brain.

Measures such as

• ointments,
• elevation,
• heat or cold applications such as ice packs, cherry pit pillows, or hay bags

can provide relief.

Sudeck’s disease is an extremely debilitating pain disorder. For this reason, supportive psychotherapy is always advisable. It helps those affected cope better with the changes in their lives.

Certain psychological stresses (“stressful life events”) can negatively influence the course of the disease. This is also the case with other chronic pain conditions. However, they are never the cause of CRPS. CRPS is a pain disorder that, for many patients, is accompanied by significant psychological consequences. Some patients exhibit excessive anxiety and avoidance behavior. Others, on the other hand, try to hide the condition and not let on that anything is wrong.

As early as the first few months of the illness, those affected notice severe physical and emotional exhaustion. They often complain of

• sleep disturbances,
• lack of motivation,
• self-doubt, and
• above all, anxiety about the future.

It is generally assumed that psychological symptoms are the result of CRPS, not its cause. Psychotherapeutic treatment is divided into several phases.

First Phase of Psychotherapeutic Treatment

In the first phase, the most important goal is to provide the patient with information about the condition that is tailored to their individual needs. Psychotherapy also aims to address the fear, frustration, and helplessness resulting from the sudden physical and psychological changes.

From one day to the next, patients find themselves limited in almost all aspects of daily life. This affects not only professional and social activities but also everyday tasks such as

• washing,
• getting dressed,
• eating, and
• driving.

At the same time, those affected often encounter little understanding from their social circle regarding their limitations. This usually leads them to withdraw from social life.

To promote mental stability, the following have proven particularly effective:

• relaxation and visualization techniques (imagining positive images) as well as
• resuming enjoyable activities

have proven effective. Medical, physical therapy, and psychotherapy measures should be coordinated on an ongoing basis. They are typically combined in a multimodal pain management approach.

Second Phase of Psychotherapeutic Treatment

In the second phase, techniques should be taught that help patients

• recognize their physical limits and
• develop appropriate strategies for managing physical strain and rest.

Third phase of psychotherapeutic treatment

In the third phase of treatment, the patient learns to

• to exercise patience and perseverance,
• to weather periods of treatment stagnation and resignation, and
• to repeatedly focus their attention on (small) progress.

Furthermore, the therapist works with the patient to develop realistic plans for reintegration into professional and personal life. These concerns should also be discussed during psychotherapy so that the therapist can refer the patient to qualified professionals.

The “CRPS Network: Strong Together” is an alliance of all CRPS self-help groups in Germany, Luxembourg, Switzerland, and Austria. It provides information on the disease, treatment options, and specialists. In addition, regional groups offer opportunities for discussion online and at regular meetings.

CRPS is a long-term condition that requires a great deal of patience. In rare cases, chronic CRPS can lead to

• render the affected body part unusable and
• to a severe disability

. Generally speaking, the earlier the condition is diagnosed and treated, the better the prognosis. However, progress is possible even after the condition has persisted for a long time.