Sickle cell crises (painful)

A painful sickle cell crisis (or vaso-occlusive crises) is the commonest manifestation of SCD and is chracterised by recurrent episodes of acute, severe pain from tissue ischemia as a result of vaso-occlusion (1).

• pain is unpredictable and frequently occurs spontaneously but may be seen after infection, exposure to cold, dehydration or in uncommon situations after emotional stress, exercise or alcohol, often no precipitating cause can be found (1,2)
• is responsible for around 90% of hospital admission in patients with SCD
• between two to three painful sites are usually seen although the number may vary (2)

Microvascular occlusion can affect any organ in the body but it is particularly common in deep muscle, periosteum and in bone marrow (3):

• infarction of the bone marrow leads to release of inflammatory mediators which activate afferent nerve fibers resulting in severe generalised bone pain (1)
• almost any bone may be involved and there is a tendency for the infarcts to become infected. Sometimes infection may occur with unusual organisms such as Salmonella.
• the bone marrow shows erythroid hyperplasia.

In males the age is important, with clustering of events around puberty, and correlates with an increase in the haemoglobin levels, to the extent where some centres may venesect patients. In women there is an association with the first week post menstruation

An association between frequent episodes of acute pain and the following factors has been observed:

• sickle-cell anaemia (when compared to HbSC disease)
• high haematocrit
• low fetal haemoglobin concentrations
• sibling history of asthma
• nocturnal hypoxaemia (4)

In sickle cell anemia patients older than 20 years, an increased frequency of pain is associated with an early death (4).

Reference:

• (1) Rees DC et al. Guidelines for the management of the acute painful crisis in sickle cell disease. Br J Haematol. 2003;120(5):744-52
• (2) Dunlop RJ, Bennett KC. Pain management for sickle cell disease. Cochrane Database Syst Rev. 2006 Apr 19;(2)
• (3) Ballas SK, et al. Definitions of the phenotypic manifestations of sickle cell disease. Am J Hematol. 2010;85(1):6-13.
• (4) Rees DC, Williams TN, Gladwin MT. Sickle-cell disease Lancet. 2010 11;376(9757):2018-31