Diagnosing Complex Regional Pain Syndrome

Currently, the is no single test which can definitively diagnose CRPS. Instead, diagnosis is made according to the guidelines of the Budapest Criteria.

The Budapest Criteria relies on the identification of 'signs' by the healthcare professional undertaking your examination, and of 'symptoms' experienced and reported by you. Not all signs and symptoms may be evident at the same time. In order to receive a diagnosis, you must experience one or more symptoms in at least three of the following four categories:

Sensory. This can include increased sensitivity  (hyperaesthesia) and/or painful sensation in response to typically non-painful stimuli (allodynia), such as tactile sensation from clothes or bedding.

Vasomotor. This can include changes in the colour or temperature of the affected area. 

Sudomotor.  This can include changes in the volume of the affected limb (swelling), as well as increased or reduced sweating. 

Motor and Trophic. This can include muscle weakness, spasms or tremors, as well as muscle wastage (atrophy) and a decreased range of motion in the affected area. Trophic changes may include changes in the growth or hair and nails, or the appearance of the skin. 

In addition, at least one sign must be evident to the healthcare provider completing your diagnostic assessment in two of the following four categories:

Sensory. This can include heightened sensitivity to painful (pinprick) stimuli (hyperalgaesia) and/or painful sensation in response to light touch or deep somatic pressure (allodynia), and/or joint movement.

Vasomotor.  Differences in temperature and/or skin colour between the affected and unaffected limb. 

Sudomotor.  This can include changes in the volume of the affected limb (swelling), as well as increased or reduced sweating. 

Motor and Trophic. This can include muscle weakness, spasms or tremors, as well as muscle wastage (atrophy) and a decreased range of motion in the affected area. Trophic changes may include changes in the growth or hair and nails, or the appearance of the skin.

Additional tests may be performed to rule out the possibility that your combination of signs and symptoms may result from any other health condition. These additional tests can include blood tests to rule out infection or immune conditions such as rheumatoid arthritis, imaging (including MRI and X-ray) to rule out conditions which can affect your joints, bone and soft tissue, and nerve conduction studies to rule out nerve damage.