A 4-year-old girl with sickle cell anaemia presents with abdominal pain. On examination, she is noted to have splenomegaly and is clinically anaemic. What is the most likely diagnosis?
During a sequestration crisis, the sickle cells cause the spleen to become grossly enlarged causing the abdominal pain as present in this case. This is more common in early childhood as repeated sequestration and infarction of the spleen during childhood gradually results in an auto-splenectomy. A sequestration crisis may result in severe anaemia, marked pallor and cardiovascular collapse due to loss of effective circulating volume.
Sickle cell anaemia is characterised by periods of good health with intervening crises
A number of types of crises are recognised:
- thrombotic, ‘painful crises’
- acute chest syndrome
- also known as painful crises or vaso-occlusive crises
- precipitated by infection, dehydration, deoxygenation
- infarcts occur in various organs including the bones (e.g. avascular necrosis of hip, hand-foot syndrome in children, lungs, spleen and brain
- sickling within organs such as the spleen or lungs causes pooling of blood with worsening of the anaemia
Acute chest syndrome
- dyspnoea, chest pain, pulmonary infiltrates, low pO2
- the most common cause of death after childhood
- caused by infection with parvovirus
- sudden fall in haemoglobin
- fall in haemoglobin due an increased rate of haemolysis