Complex regional pain syndrome (CRPS) / algodystrophy is characterized by significant, chronic pain in en hand or foot accompanied by changes in hair growth, heat regulation, often also muscle wasting and reduced bone calcium (osteopenia) in the painful area. The condition may resemble rheumatic inflammation, but inflammation tests such as CRP and SR are expected to be normal. Classic algodystrophy is also referred to as reflex dystrophy, shoulder-hand syndrome and Sudeck's atrophy.
Early symptoms are severe, burning pain that is out of proportion to the underlying cause. This pain begins at the site of the triggering injury and then spreads over a somewhat larger area. Increased skin temperature, nail and hair growth and red skin (erythema) can be seen. If the disease continues to develop, hair growth is often reduced, nails become brittle and muscles become weaker. The skin temperature begins to decrease and eventually leads to a "cold" hand or foot. Some develop persistent muscle weakness, loss of muscle mass and intractable pain that can last for a number of years. Some also develop pain in the opposite arm/leg. (Shim H, 2019).
Stage 1 (acute/warm stage): acute burning pain in more than 90%, often more than the injury would indicate. Hypersensitivity to pricking or touching the skin is common. Examination may reveal swelling, increased sweating, heat in the skin and increased or decreased hair growth.
Stage II: (Dystrophic/Cold stage): The manifestations, partly also the pain from stage I gradually disappear. The skin becomes cool, possibly bluish discolored (cyanotic).
Stage III (late injury): Characterized by thin skin, muscle wasting and reduced function.
Medical history maps any triggering cause and symptom development (see above).
Clinical the spread, appearance and temperature of the skin and whether the muscles and nervous system are impaired are assessed. Joints are expected to be normal in shape and movement.
Blood tests expected to be normal.
Imaging can show reduced calcium content by X-ray, CT or DEXA measurement (bone density/osteoporosis measurement).
Nerve examinations with neurography and electromyography (EMG) can show changes, but not in all cases.
Thermography measures skin temperature over the affected area and compares with the healthy side.
The diagnosis is based on symptoms, examination findings and disease course (see above). Diagnostic criteria for CRPS according to The International Association for the Study of Pain (IASP). Classification criteria: Budapest criteria of 2003 (Urits I. 2018)
Similar conditions, differential diagnoses
- Blood clot / thrombosis (by Antifosfolipid syndrome and other predisposing conditions). Not pain
- Fracture injury (fracture)
- Nervous system disorders
- Causalgia: Persistent pain or hypersensitivity after a nerve injury, but not necessarily limited to the nerve's supply area. Swelling (oedema), skin changes with signs of altered blood circulation in the skin or abnormal sweating in the painful area. No other conditions can explain the degree of pain and the reduced function
- Kidney damage, plexus injury and more)
- RS3PE Both hands swollen. High CRP and SR in blood tests. Elderly people.
Early treatment is important and is often multidisciplinary with physiotherapy and in some cases also psychological measures. Control of pain with painkillers (analgesics), especially for neuropathic pain. Both gabapentin and amitriptyline have shown efficacy. Use of NSAIDs og cortisone drugs is uncertain. Bisphosphonates that are otherwise used against osteoporosis / osteoporosis can reduce pain, but good studies are in short supply (O'Connell NE, 2013).
The condition lasts for several months. Some people have symptoms for more than five years.