Dr Dominic Hegarty discusses the early diagnosis and management of complex regional pain syndrome (CRPS), a debilitating, painful condition in a limb, in the primary care setting.
Complex regional pain syndrome (CRPS) is a debilitating, painful condition in a limb associated with sensory, motor, autonomic, skin and bone abnormalities. It was originally recognised in 1872 during the American Civil War as a result of gunshot injuries to limbs, but the possibility of it being present in ‘civilian’ life is relatively recent. Pain is typically the leading symptom, but is often associated with limb dysfunction and psychological distress. CRPS can strike at any age and affects both men and women, although it is five times more common in women. The average age of affected individuals ranges between 55-70 years. Children do not get it before age five and only very rarely before age 10, but it is not uncommon in teenagers. A European epidemiological study highlighted that the incidence of CRPS is more common than previously thought, with an incidence of 26 per 100,000 population. For comparison, the incidence of multiple sclerosis in the UK is estimated at four in 100,000.
Overall, 85 per cent of patients will have substantial pain reduction within the first one-to-two years after disease onset. However, only 30 per cent of patients consider themselves fully recovered even six years after disease onset. Only 40 per cent of people who worked before will return to their prior work. CRPS which has not improved early is less likely to improve later.
The physical, psychological and economical costs are enormous. Prompt diagnosis and early treatment is required to avoid secondary physical problems related to disuse of the affected limb and the psychological consequences of living with undiagnosed chronic pain.
Guidelines have recently been developed for diagnosis and management in the context of primary and secondary care. The International Association for the Study of Pain, recently held their specialist group meeting in Cork (www.CRPSCork2017.com), see meeting report on page 30.
What are the symptoms of CRPS?
The symptoms may present within the first four-to-six weeks following an injury. However, it may present later in some individuals. A key symptom is prolonged pain that may be constant and, in some people, extremely uncomfortable or severe. The pain may be described as a ‘burning’ or ‘pins and needles’ sensation, or as if someone is squeezing the affected limb. The pain may spread to include the entire arm or leg, even though the precipitating injury might have been only to a finger or toe. There is often increased sensitivity in the affected area, so that even light touch or contact is painful (called allodynia).
The severity of CRPS can vary as it progresses through different stages but there are certain elements as described by the Budapest Criteria (2010) (Table 1).
People with CRPS also experience (Figure 1):
Constant or intermittent changes in temperature, skin colour, and swelling of the affected limb. This is due to abnormal microcirculation caused by damage to the nerves controlling blood flow and temperature. An affected arm or leg may feel warmer or cooler compared to the opposite limb. The skin on the affected limb may change colour, becoming blotchy, blue, purple, pale, or red.
Changes in skin texture on the affected area; it may appear shiny and thin.
Abnormal sweating pattern in the affected area or surrounding areas.
Changes in nail and hair growth patterns.
Stiffness in affected joints.
Problems co-ordinating muscle movement, with decreased ability to move the affected body part.