Some physiotherapists in the past have used ice as a therapy for Complex Regional Pain Syndrome. However, it is very important to note that doctors, specialists and healthcare professionals recommend that you never put ice, nor use any cold or hot/cold contrast therapy, on the limb that has been affected by CRPS.
Ice can cause symptoms to come on faster and can even cause frostbite if the ice is held on too long (Nishikawa, M. et al 2008). In the case study by Nishikawa, M. et al (2008), a patient, despite repeated cautions against cold-induced injury, continued all-day cooling of the CRPS arm. She was later admitted to hospital once again with extensive skin necrosis on the left arm and a contracted left elbow joint. The areas of skin necrosis exactly matched the sites where she had applied ice packs.
According to the RSDGuide (2013), "Application of any type of a cold compress to an area that is affected with CRPS reduces blood flow to the area. It also damages the myelin sheath surrounding the nerve tissue and constricts blood vessels. CRPS makes it difficult for the blood vessels and myelin sheath to recover, possibly causing nerve and blood vessel damage and further aggravating the condition."
In a case study article by Hooshmand, H. et al. (2004), they stated that the reason why cryotherapy should NOT be used is that "…use of cryotherapy can cause permanent somatosensory and thermosensory (sympathetic) nerve damages with contrasting complications of focal somatic myelinated nerve fibers damage and focal pain, versus C-thermoreceptor nerves (CTN) damage causing neuropathic regional pain and inflammation (skin ulcers). Long-term exposure and extreme hypothermia can cause permanent nerve damages."
Hooshmand, H. et al.(2004) also stated that "..prolonged and repetitive ice application can cause damage to the myelinated motor and sensory nerves. The myelin sheath is rich in lipids. Ice application results in solidification and hardening of the myelin lipid, similar to application of ice on melting butter. This can lead to an arrest of motor and sensory nerve conduction. Even brief ice application, lasting no more than 20 minutes, can cause transient paralysis of the motor and sensory nerve fibers, lasting as long as one year (1)."