Sickle cell disease (SCD) is the most common inherited clinically significant blood disorder, affecting at least 100 000 Americans and millions around the world. Red blood cells (RBCs) with sickle haemoglobin (HbS) are prone to haemolysis and microvascular obstruction, resulting in anaemia and the potential for tissue ischaemia as well as multiorgan complications.1 The most frequent acute complication of SCD is pain, classically termed ‘acute pain crisis’ (APC). Pain related to SCD is thought to be caused by vaso-occlusion resulting from RBC aggregation and inflammation, which leads to tissue ischaemia, subsequent reperfusion and pain.2 However, there are other potential causes of acute pain in people with SCD including neuropathic pain, exacerbations of chronic pain and pain caused by other aetiologies such as musculoskeletal injury or infection. Thus, each pain episode must be individually assessed for the potential of vaso-occlusion, since it can lead to organ dysfunction, as well as for other non-SCD causes of pain.
