CRPS has characteristics similar to those of other disorders, such as shoulder-hand syndrome, which sometimes occurs after a heart attack and is marked by pain and stiffness in the arm and shoulder; Sudeck syndrome, which is prevalent in older people and women and is characterized by bone changes and muscular atrophy, but is not always associated with trauma; and Steinbrocker syndrome, which includes symptoms such as gradual stiffness, discomfort, and weakness in the shoulder and hand. Erythromelalgia
also shares many components of CRPS (burning pain, redness, temperature
hypersensitivity, autonomic dysfunction, vasospasm), they both involve
small fiber sensory neurosympathetic components. Erythromelalgia
involves a lack of sweating, whereas CRPS often involves increased
sweating. Subvariations of both exist. New information lends credibility
to previous positions that this is an autoimmune response disease that
can be caused by injury, non injury, and can progress from the injured
location throughout the entire body, to include optic nerves, ear
nerves, and other facial nerves. Regarding the facial nerves, the eyes
seem to be most vulnerable, with no specific pattern as to one or both.
It also has the ability to affect sexual function in both the male and
female anatomy, though the ability to engage in sexual activity is
limited by the disease itself. There is further information that some
cases may have a genetic predisposition for the disease, as with other
autoimmune diseases. Myasthenia Gravis is another disease that mirrors many of the symptoms of CRPS.