Sympathetic Pain Syndrome
Complex Regional Pain Syndrome
Complex Regional Pain Syndrome
(CRPS) is a chronic pain condition. A patient with CRPS has
pain as well as changes in blood flow, sweating, and
swelling in the painful area. Sometimes the condition leads
to changes in the skin, bones and other tissues. It may also
become hard for a patient with CRPS to move the painful body
The patient's arms or legs are usually involved, but CRPS
may affect any part of the body, such as the face or trunk.
In some patients, many different areas of the body are
affected. CRPS can be progressive (meaning that it gets
worse at one site or spreads to other sites), or it can stay
the same for a long time or even improve on its own.
CRPS usually develops after an injury. The injury may be
to the skin, bone, joints or tissue. This type of CRPS has
been called reflex sympathetic dystrophy.
CRPS can also develop after any type of injury to major
nerves. This type has been called causalgia.
The injury that leads to CRPS may be only minor, and
sometimes a patient cannot remember any injury or event that
caused CRPS to start.
Symptoms Needed to Make the Diagnosis of CRPS
These are the symptoms that doctors use to decide whether or
not a patient has CRPS:
Pain that is constant or almost constant, with:
- pain caused by things that do not usually cause
pain, such as clothing, wind, cold or a light touch to
the skin (called "allodynia"), and/or
- severe pain when only a slight pain would be
expected, such as when a doctor lightly pricks the skin
with a pin (called "hyperalgesia")
Having some of the following in the painful area:
- changes in skin color (mottled, purple-bluish, red)
- skin temperature that is not normal (either hotter
or colder than other areas)
- either more or less sweating in the area
Reflex sympathetic dystrophy syndrome (RSDS) is a
condition that features a group of typical symptoms,
including pain (often "burning" type), tenderness, and
swelling of an extremity associated with varying degrees of
sweating, warmth and/or coolness, flushing, discoloration,
and shiny skin.
What causes reflex
RSDS is also referred to as "the shoulder-hand syndrome,"
"causalgia," and "Sudeck's atrophy." The exact mechanism of
how RSDS develops is poorly understood. The theories include
irritation and abnormal excitation of nervous tissue,
leading to abnormal impulses along nerves that affect blood
vessels and skin. A variety of events can trigger the
condition, including trauma, surgery, heart disease,
degenerative arthritis of the neck, stroke or other brain
diseases, nerve irritation by entrapment (such as carpal
tunnel syndrome) or shingles, shoulder problems, breast
cancer, and drugs for tuberculosis and barbiturates. There
is no associated event in one-third of patients.
What are the symptoms of
reflex sympathetic dystrophy?
The onset of the RSDS symptoms may be rapid on gradual.
The condition may not display all features. It has been
bilateral in up to half of the patients. There are several
- Acute: (three to six months) burning, flushing,
blanching, sweating, swelling, pain, and tenderness.
This stage can show early x- ray changes of patchy bone
- Dystrophic: (three to six months) early skin changes
of shiny, thickened skin and contracture with persistent
pain, but diminished swelling and flushing.
- Atrophic: (may be long-standing) loss of motion and
function of the involved hand or foot with contracture
(flexed scarring process), thinning of the fatty layers
under the skin. X-ray can show significant osteoporosis.