‘Red flags’ or clinical features indicative of potentially serious pathology (Box 12.10)

Acute or acute-on-chronic situations swelling, erythema, marked reduction in range of motion of a joint (infection or other inflammation) systemic features in the absence of trauma (infection or other inflammation) rapid swelling of a joint following trauma (haemarthrosis) pain and/or abnormal sensation associated with loss of power or altered reflexes (radiculopathy) Chronic or persistent situations unusually severe pain, swelling, temperature change, cyanosis/pallor and immobility in a limb or part thereof, often following a minor injury (complex regional pain syndrome). diffuse limb pain in the absence of other signs (somatic referred pain) pain and/or abnormal sensation associated with loss of power or altered reflexes (radiculopathy) persistent localised pain uninfluenced by posture or movement (bone disease)

NB1: These red flags apply equally to joints of lower and upper limb.