sickle cell anaemia

Question 1

what kind of mutation is sickle cell anaemia?

what does sickle cell cause?

Answer 1

• homozygous
• autosomal recessive
• chronic haemolytic anaemia (of about 90g/dl)

Question 2

when does sickle cell disease tend to present?

Answer 2

• 3-6 months of age when HbF levels are falling

Question 3

what kind of symptoms do they have in sickle cell anaemia?

Answer 3

• anaemia
• jaundice
• pallor, lethargy
• growth restriction/ FTT
• general weakness
• painful joints

Question 4

what is the most common causes of anaemia in sickle cell disease?

Answer 4

• splenic sequestration
• transient red cell aplasia
• hyperhaemolysis (in severe infection)

Question 5

what is a sickle cell crisis?

Answer 5

• obstruction of microcirculation by sickled RBCs causing ischaemia
• occlusion of small vessels causes pain

Question 6

how does a sickle cell crisis present

Answer 6

• joint pain
• tachypnoea
• neuro signs
• acute abdo pain
• retinal occlusion
• large vessel disease (thrombotic strokes, acute sickle chest syndrome and placental infarction

Question 7

when do you need an urgent referral to hospital?

Answer 7

• severe pain
• dehydration
• severe sepsis
• acute chest syndrome (tachypnoea)
• neurological symptoms
• acute enlargement of spleen
• marked increased in jaundice

Question 8

what infection may cause an aplastic crisis?

what is aplastic crisis?

Answer 8

• parvovirus B19

- drop in Hb over one week needing transfusion

Question 9

what disease does parvovirus cause?

Answer 9

• Fifth disease

- slapped check syndrome

Question 10

what would you find on an FBC in children with sickle cell?

blood film?

how is a diagnosis made?

Answer 10

• Hb between 60-80
• high reticulocyte count (10-20%)
• blood film shows sickled erythrocytes and features of hyposplenism
• positive sickling test on electrophoresis

Question 11

how can you screen for sickle cell anaemia?

Answer 11

• heel prick

- prenatal diagnosis (amniocentesis, CVS and FBS)

Question 12

what is the management? (3)

Answer 12

• oral penicillin prophylaxis
• blood transfusion/ partial exchange transfusion in acute life-threatening sickle cell
• hydroxyurea (hydroxycarbamide)
  reduces the frequency of crises, ACS, need for transfusions

Question 13

what is the only curative measure for sickle cell?

what must be screened for in sickle cell children?

Answer 13

• bone marrow transplant

- transcranial doppler ultrasound in children aged 2-16