Haem - paediatric haematology

Question 1

Why are children more predisposed to vitamin deficiency than adults?

Answer 1

Rapid growth of a child

• eg iron, folate

Question 2

How does a child’s response to infection differ to an adults (a v general answer)

Answer 2

Children respond with a lymphocytosis

Question 3

Which enzyme level in RBCs differs in neonates vs adults?

Answer 3

G6PD concentration is 50% higher in neonates

Question 4

3 causes of polycythemia in a foetus/neonate?

Answer 4

1. Twin twin transfusion
2. Intrauterine hypoxia
3. Placental insufficiency

Question 5

4 causes of anaemia in foetus/neonate

Answer 5

1. Twin-to-twin transfusion
2. Fetal to maternal transfusion
3. Placental or cord bleeding
4. Parvovirus infection

Question 6

Which anticoagulant drug should not be used in pregnant mother? What effects could it have on the baby?

Answer 6

Warfarin

Fetal deformity + haemorrhage

Question 7

1 way in which the intrauterine environment can have an effect later in childhood?

Answer 7

First mutation that subsequently leads to childhood leukaemia often occur sin utero

Question 8

Congenital leukaemia - in which particularly pt group is this common?

How does it differ to ALL?

Answer 8

Associated with Down’s syndrome

It affects megakaryocytic lineage and remits spontaneously!!!

Question 9

How does the following differ in neonates vs adults?

Hb
WBC
RBC size

Answer 9

Hb is higher
WBC is higher
RBCs are larger

Question 10

3 forms of Hb - what are they? what globin chains are in them?

Answer 10

A - a2b2
A2-a2delta2
F - a2gamma2

Question 11

Which Hb form is predominant in adulthood?

Answer 11

HbA

Question 12

Which Hb form is present in the foetus and not in the adult?

Answer 12

HbF

Question 13

How does SCA lead to crises?

Answer 13

Sickled cells become adherent to endothelium –> obstruction occurs and retrograde capillary obstruction

Question 14

What induces crises in sickle cell trait?

Answer 14

Hypoxia –> sickling of cells

Question 15

ββS - what is this

Answer 15

Sickle cell trait

Question 16

βSβS - what is this

Answer 16

SCA

Question 17

βSβc - what is this?

Answer 17

Sickle cell/haemoglobin C disease - milder than SCA!

Question 18

βSβThal - what is this?

Answer 18

Sickle cell/beta thalassemia

Question 19

If Guthrie test is not done, when does SCA present and why?

Answer 19

3-6 months of birth

The defect is in the globin chain, which is in HbA. HbA is not made until 3-6 months age

Question 20

what is hand-foot syndrome? why does it occur in first few years of life?

Answer 20

Swelling and pain of hands and feet due to red marrow infarction

Red marrow is only present in hands and feet until 2 yo.

Question 21

What is splenic sequestration? When does it tend to occur?

Answer 21

Pooling of blood cells in spleen –> splenomegaly–> Hb falls acutely

young children

Question 22

Why does splenic sequestration not happen in older children or adults?

Answer 22

Recurrent infarction –> spleen is small and fibrotic

Question 23

When does risk of hyposplenism increase?

Answer 23

As risk of splenomegaly wanes

Question 24

2 particular infections to worry about in SCA?

Answer 24

Pneumococcus

Parvovirus

Question 25

Consequence of first exposure to parvovirus B19 in SCA child?

Answer 25

Red cell aplasia

Question 26

Why is folic acid requirement higher in SCD? 3 reasons

Answer 26

1. Growth spurts
2. shorter RBC lifespan
3. Hyperplastic erythropoeisis

Question 27

Mx of SCD in infant and child? 4 points

Answer 27

1. accurate Dx
2. Educate parents
3. VACCINATE
4. Prescribe folic acid and penicillin

Question 28

A 6-year-old Afro-Caribbean boy presents with chest and abdominal pain; Hb is 63 g/l, MCV 85 fl and blood film shows sickle cells—likely diagnosis?

sickle cell trait/SCA/Sickle cell beta thalassemia

Answer 28

SCA.

sickle cells and anaemia are not seen in sickle cell trait unless v hypoxic

Question 29

What’s the difference between thalassemia major and minor?

Answer 29

Major = requires transfusion for survival
Minor = Sx-atic and anaemic but doesn't require transfusion

Question 30

What is beta thalassemia

Answer 30

having an abnormal copy of the beta globin gene

Question 31

Clinical Fx of poorly treated thalassemia

Answer 31

Anemia = HF, growth retardation

Erythropoietic drive = splenomegaly, bone expansion

Fe overload = HF, gonadal failure

Question 32

Fe overload - how is this managed?

Answer 32

Chelating agent = desferioxamine

Question 33

7yo AC boy
Severe anemia
MCV upper limit of normal
Normal platelets
Irregularly contracted cell = Hb has precipitated into one part of the RBC
Some large cells = reticulocytes

Answer 33

G6Pd deficiency

Question 34

Advice to a mother of a G6PD deficiency child?

Answer 34

Warn mother than infections can lead to haemolysis

Avoid some drugs
Avoid moth balls and fava beans