Complex Regional Pain Syndromes Differential Diagnoses

Updated: Jun 20, 2018
  • Author: Gaurav Gupta, MD; Chief Editor: Stephen A Berman, MD, PhD, MBA  more...
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DDx

Diagnostic Considerations

Differential Diagnosis

The risk of overdiagnosing CRPS must be taken into account. A detailed history and physical examination, as well as the aforementioned specifications, including testing, are necessary to differentiate CRPS from other neuropathic and pain syndromes.

Neuropathy (eg, diabetic polyneuropathy) may also present with spontaneous pain, skin color changes, and motor deficit that are distinguished from CRPS by the patient’s history and their symmetrical distribution. Furthermore, all kinds of inflammatory, rheumatological, and infectious conditions might induce intense unilateral skin warming. Unilateral arterial or venous occlusive diseases can cause unilateral pain and vascular abnormalities, and therefore must be excluded when diagnosing CRPS. The repetitive artificial occlusion of blood supply to one limb can be seen in psychiatric, factitious disorders when individuals induce secondary structural changes in the blood vessels and cause abnormalities in perfusion that mimic the symptoms and signs of CRPS.

Posttraumatic neuralgia

Many patients with posttraumatic neuropathy have pain but not the full clinical profile of CRPS type II. In these cases, pain is located largely within the territory of the injured nerve, which contrasts with patients with CRPS type II. Although patients with neuropathy often describe the pain as burning, they exhibit a less complex clinical picture than patients with CRPS type II and do not show marked swelling or the progressive spread of symptoms.

The principal symptoms for posttraumatic neuropathy are spontaneous burning pain, hyperalgesia, and mechanical allodynia. These sensory symptoms are confined to the territory of the affected peripheral nerve, although the allodynia may extend beyond the nerve territory's border by some centimeters. Both spontaneous and evoked pain is felt superficially, not deep inside the extremity, and the intensity of both is independent of the position of the extremity.

Patients with posttraumatic neuropathy usually obtain relief with sympatholytic procedures, although much less often than patients with CRPS. Following the IASP classification, it is possible to choose the term posttraumatic neuralgia for this type of neuropathic pain (pain within the territory of the lesioned nerve). However, the new definition of CRPS type II also includes the statement that symptoms can be limited to the territory of a single peripheral nerve. Therefore, the term CRPS type II could be applied to these localized posttraumatic neuropathies, even though they are different syndromes with different underlying mechanisms, which highlights the problems with this definition of CRPS II.

Diagnostic considerations

  • CNS

    • Brain (stroke, neoplasm, encephalitis)

    • Spinal cord (trauma, transverse myelitis, either structural or tumor-related syringomyelia)

    • Tabies dorsalis

    • Multiple sclerosis

    • Poliomyelitis

  • Radiculopathy

    • Structural (eg, due to structural impingement of a diskal, osteophyte-, or tumor-related nature)

    • Metabolic (eg, diabetes, vasculitis infectious)

    • Neoplastic

  • Plexopathy

    • Infectious

    • Autoimmune/idiopathic

    • Tumor (primary or secondary neoplasm), especially Pancoast syndrome

    • Trauma (macro or cumulative)

    • Entrapment (thoracic outlet syndrome)

  • Neuropathy

  • Vascular disorders

    • Raynaud phenomena

    • Peripheral atherosclerotic disease

    • Arterial insufficiency

    • Phlebothrombosis

  • Monomelic amyotrophy

  • Psychological

  • Movement disorders

  • Metabolic or systemic (eg, renal failure, amyloidosis)

  • Autoimmune or rheumatological disorder

  • Infectious (eg, viral, fungal, Lyme) Iatrogenic (eg, prescribed medication)

  • Demyelinating (CIDP, paresis or sensory deficiency due to multiple sclerosis)

  • Toxic exposure (eg, vinca alkaloids, heavy metals)