Haematology Flashcards
What are the types of causes of anaemia in children?
reduced rbc production
increased haemolysis
blood loss
Give examples of causes of reduced rbc production
ineffective erythropoiesis: - iron deficiency - B12/folate deficiency - JIA - chronic renal failure - lead poisoning rbc aplasia: - parvovirus b19 - diamond blackfan - transient erythroblastopenia of childhood
Give examples of causes of increased rbc haemolysis
haemolytic disease of the newborn autoimune haemolytic anaemia haemoglobinopathies: thalassaemia, sickle cell rbc enzyme - G6PD deficiency roc membrane - spherocytosis
What can cause blood loss leading to anaemia?
meckels diverticulum
VW disease
what are causes of iron deficiency anaemia?
inadequate intake
malabsorption
blood loss
what are the clinical features of iron deficiency anaemia?
asymptomatic until <6-7g/dl tire easily slower feeding pica pale?
What are diagnostic clues of iron deficiency anaemia?
low MCV and MCH - microcytic, hypochromic
low serum ferritin
give causes of microcytic anaemia
- Iron deficiency
- Beta-thalassaemia trait
- Alpha thalassaemia
- Anaemia of chronic disease
What is the management of iron deficiency anaemia?
- Change diet
- Oral iron supplements - Sytron (sodium iron edetate), Niferex
Continue supplementation until Hb is normal and then for a minimum of 3 months
why should children w iron deficiency w normal hb still be treated?
iron is essential for normal brain development and IDA is associated w behavioural and intellectual deficiencies
What are the 3 main causes of red cell aplasia?
congenital red cell hyperplasia
transient erythroblastopenia of childhood
parvovirus b19
What are the diagnostic clues of red cell aplasia
low reticulocyte count despite low hb
normal bilirubin
negative direct Coombs
absent red cell precursors on bone marrow examination
what are some congenital abnormalities found in diamond blackfan anaemia?
short stature
abnormal thumbs
What is the rx of diamond blackfan anaemia?
oral steroids
monthly rbc transfusions if steroid unresponsive
What is the difference between diamond blackfan and transient erythroblastopenia of childhood?
same haematological features but TEC always recovers
What are the effects of haemolytic from increased roc breakdown?
anaemia
hepatosplenomegaly
increased blood levels of unconjugated bilirubin
XS urinary urobilinogen
What are the diagnostic clues of haemolytic anaemia?
o Reticulocyte count (lilac on blood film)
o Unconjugated bilirubinaemia (present in the blood) and urinary urobilinogen
o Abnormal appearance of rbc’s on blood film e.g. Sickle cell, spherocytes, v hypochromic)
o +ve coombs
o rbc precursors in the bone marrow
wat is the genetic inheritance of hereditary spherocytosis?
autosomal dominant
how does spherocytosis lead to haemolysis?>
reduction in surface to volume ratio causes them to become spheroidal, they’re less deformable than normal rbc’s and are destroyed in the microvasculature of the spleen
what are the clinical features of hereditary spherocytosis?
Highly variable
Can be asymptomatic
i. Jaundice
ii. Anaemia
iii. Splenomegaly - depending on rate of haemolysis
iv. Aplastic crisis - caused by parvovirus B19 infection
v. Gallstones - due to bilirubin excretion
how is a diagnosis of hereditary spherocytosis made?
blood film- spherocytes
direct ab test if no FH of HS
what is the management of mild spherocytosis
oral folic acid
what is the management of severe spherocytosis?
splenectomy if poor growth and severe signs for >7y.o due to risk of sepsis
what is the management of aplastic crises?
½ blood transfusions over 3-4 weeks when no rbcs are produced