Complex Regional Pain Syndrome


Complex Regional Pain Syndrome medically abbreviated as CRPS, refers to a chronic condition that mostly affects the hand with swelling, stiffness, an intense burning pain and some discoloration. CRPS may also involve the arms, legs and the feet of an affected person.

complex regional pain syndrome image

This can take place after any trauma or injury, stroke or cases of heart attack, or those who underwent with surgical procedures. Other terms of CRPS are shoulder-hand syndrome, reflex sympathetic dystrophy, causalgia, Sudeck’s atrophy, and reflex neurovascular dystrophy.

CRPS can be observed among men and women, though most cases are with women. It may happen at any age and all individuals have chances to get it, usually those who are nearly in their 40s. The elderly is having a rare chance, not noted among children before reaching 5 years old and not often found among a group of teenagers.

Symptoms of Complex Regional Pain Syndrome

The triggering factors leading to CRPS differs, yet they are presented with the same set of symptoms and they go through the same stages of the disease condition which are as follows:

complex regional pain syndrome symptoms

Stage I/Acute Stage – This can last with a period of 3 months and the symptoms are:

  • Constant burning pain that is longer lasting
  • Increased sensitivity with touch
  • Swelling and joint stiffness
  • Affected limb with increased warmth and redness
  • Excessive sweating
  • Nail and hair growth is faster than normal

Stage II/Dystrophic Stage – This can be noted from 3 to 12 months and the symptoms are:

  • More constant swelling
  • Skin wrinkles disappear
  • Cooler skin temperature
  • Brittle fingernails
  • Pain becomes widespread
  • Increase in joint stiffness
  • Affected area more sensitive to touch

Stage III/Atrophic Stage – This happens after 1 year and the symptoms are:

  • Affected area has pale skin, appears dry and shiny, tightly stretched
  • Stiffness of area with lesser chance of having its motion to be back
  • Decreased pain
  • May spread to other body areas


The exact cause of CRPS is not specifically known; however, there are two types of CRPS which can hypothetically explain the possible reasons of its occurrence.

The triggering factors are not well understood as to why it may end up with CRPS, but some studies have mentioned that it might be due to an impaired interaction between the central nervous system and peripheral nervous system, and the inflammatory responses which are inappropriate.

The consensus group among pain medicine experts who are being gathered in 1994 by the International Association for the Study of Pain (IASP) came to agree and successfully made a diagnostic criteria for reflex sympathetic dystrophy (RSD) as CRPS Type I and causalgia as the CRPS Type II.

Researches felt some levels of ambiguity in the naming of criteria; however, clinical research studies are utilized by the IASP to support the types of CRPS as identified.

crps types


This is formerly referred to as reflex sympathetic dystrophy (RSD), Sudeck’s atrophy, reflex neurovascular dystrophy (RND), or algoneurodystrophy where patients do not have any observable nerve lesions. It happens when any form of an illness or injury does not directly cause specific damage with a nerve in the affected site.


This type is also formerly referred to as causalgia, where a patient can be seen to have evidences of observable nerve damage. It follows after a distinct nerve injury affecting the site which is exposed to any damage.


There is no specific single diagnostic examination to confirm a CRPS problem of a patient. The diagnosis is mostly based after a thorough medical history taking by physicians and where the clinical manifestations are seen to match the definition of any CRPS type.

Here is a set of clinical diagnostic criteria as being proposed and set by the IASP:

  • Presence of continuing pain which is not proportionate with the stated cause or event
  • At least 1 symptom reported as manifested from at least 3 of the categories stated:
  • Sensory, such as hyperesthesia or with allodynia
  • Vasomotor, such as changes in skin color or asymmetrical skin color, asymmetry in temperature
  • Sudomotor/edema, such as presence of an edema, changes in sweating or asymmetrical sweating
  • Motor or trophic, such as trophic changes noted in the hair, nail or skin; dysfunction in motor activities and decreased range of motion
  • Having at least 1 sign at the time of evaluating the patient from at least 2 categories:
  • Sensory, such as hyperalgesia when pinprick is done or an allodynia with light touch or with movements of joints
  • Vasomotor, such as actual evidences noted with asymmetrical temperature or with skin color changes
  • Sudomotor/edema, such as presence of actual edema, or changes in sweating with some asymmetry
  • Motor/trophic, such as observable evidence in motor dysfunctions like weakness or tremor; trophic changes found in hair or nails and the decreased range of motion activities done


Available therapies for CRPS are:

  • Rehabilitation therapy to keep the painful limb move through an exercise program
  • Psychotherapy to improve the coping and recovery from CRPS

Medications such as:

  • Antidepressants
  • Nonsteroidal anti-inflammatory drugs for pain
  • Corticosteroids for swelling and inflammation
  • Topical local anesthetic creams and patches for pain

Emerging pain treatments available for CRPS are:

  • Intravenous immunoglobulin /(IVIG)
  • Ketamine
  • Hyperbaric oxygen

ICD 9 Code

The 2013 ICD-9-CM Diagnosis Code 337.22 is a billable medical code indicating a diagnosis used for reimbursement claims of CRPS, with a service date on or before September 30, 2015. The ICD-10-CM code, which is the 2015 /16 ICD-10-CM G90.529, is being used for claims which are on or after October 1, 2015.


complex regional pain syndrome image



  1. Complex regional pain syndrome tests, treatment, prevention at
  2. Complex Regional Pain Syndromes – Overview, Presentation, DDx, Workup, Treatment, Medication, Follow-up
  4. Varenna M, Adami S, Rossini M; et al. (March 2013). “Treatment of complex regional pain syndrome type I with neridronate: a randomized, double-blind, placebo-controlled study”. Rheumatology 52 (3): 534–42.
  5. Niesters, M; Martini, C; Dahan, A (February 2014). “Ketamine for chronic pain: risks and benefits.”. British Journal of Clinical Pharmacology 77 (2): 357–67.
  6. Brunner F, Schmid A, Kissling R, Held U, Bachmann LM (January 2009). “Biphosphonates for the therapy of complex regional pain syndrome I–systematic review”. European Journal of Pain 13 (1): 17–21.

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