Haem - paediatric haematology Flashcards
Why are children more predisposed to vitamin deficiency than adults?
Rapid growth of a child
- eg iron, folate
How does a child’s response to infection differ to an adults (a v general answer)
Children respond with a lymphocytosis
Which enzyme level in RBCs differs in neonates vs adults?
G6PD concentration is 50% higher in neonates
3 causes of polycythemia in a foetus/neonate?
- Twin twin transfusion
- Intrauterine hypoxia
- Placental insufficiency
4 causes of anaemia in foetus/neonate
- Twin-to-twin transfusion
- Fetal to maternal transfusion
- Placental or cord bleeding
- Parvovirus infection
Which anticoagulant drug should not be used in pregnant mother? What effects could it have on the baby?
Warfarin
Fetal deformity + haemorrhage
1 way in which the intrauterine environment can have an effect later in childhood?
First mutation that subsequently leads to childhood leukaemia often occur sin utero
Congenital leukaemia - in which particularly pt group is this common?
How does it differ to ALL?
Associated with Down’s syndrome
It affects megakaryocytic lineage and remits spontaneously!!!
How does the following differ in neonates vs adults?
Hb
WBC
RBC size
Hb is higher
WBC is higher
RBCs are larger
3 forms of Hb - what are they? what globin chains are in them?
A - a2b2
A2-a2delta2
F - a2gamma2
Which Hb form is predominant in adulthood?
HbA
Which Hb form is present in the foetus and not in the adult?
HbF
How does SCA lead to crises?
Sickled cells become adherent to endothelium –> obstruction occurs and retrograde capillary obstruction
What induces crises in sickle cell trait?
Hypoxia –> sickling of cells
ββS - what is this
Sickle cell trait
βSβS - what is this
SCA
βSβc - what is this?
Sickle cell/haemoglobin C disease - milder than SCA!
βSβThal - what is this?
Sickle cell/beta thalassemia
If Guthrie test is not done, when does SCA present and why?
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
what is hand-foot syndrome? why does it occur in first few years of life?
Swelling and pain of hands and feet due to red marrow infarction
Red marrow is only present in hands and feet until 2 yo.
What is splenic sequestration? When does it tend to occur?
Pooling of blood cells in spleen –> splenomegaly–> Hb falls acutely
young children
Why does splenic sequestration not happen in older children or adults?
Recurrent infarction –> spleen is small and fibrotic
When does risk of hyposplenism increase?
As risk of splenomegaly wanes
2 particular infections to worry about in SCA?
Pneumococcus
Parvovirus
Consequence of first exposure to parvovirus B19 in SCA child?
Red cell aplasia
Why is folic acid requirement higher in SCD? 3 reasons
- Growth spurts
- shorter RBC lifespan
- Hyperplastic erythropoeisis
Mx of SCD in infant and child? 4 points
- accurate Dx
- Educate parents
- VACCINATE
- Prescribe folic acid and penicillin
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
SCA.
sickle cells and anaemia are not seen in sickle cell trait unless v hypoxic
What’s the difference between thalassemia major and minor?
Major = requires transfusion for survival Minor = Sx-atic and anaemic but doesn't require transfusion
What is beta thalassemia
having an abnormal copy of the beta globin gene
Clinical Fx of poorly treated thalassemia
Anemia = HF, growth retardation
Erythropoietic drive = splenomegaly, bone expansion
Fe overload = HF, gonadal failure
Fe overload - how is this managed?
Chelating agent = desferioxamine
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
G6Pd deficiency
Advice to a mother of a G6PD deficiency child?
Warn mother than infections can lead to haemolysis
Avoid some drugs
Avoid moth balls and fava beans
