Complex regional pain syndrome (CRPS)
This is a rare condition commonly seen in the arms and hands, and to a lesser extent, in the legs and feet after an injury or occasionally an operation. There are two types, but in either case there is an exaggerated pain response at tissue level and within the brain. Limbs affected by CRPS will be red, shiny and swollen. They will be extremely painful to the touch and painful to move, but in many cases the injury will have been trivial. The causes are still unclear, but CRPS requires careful management although early intervention with appropriate antineuropathics is helpful. Nerve blocks may be helpful if maintaining pain although it can take several months worth of treatment.