Haematology: Anaemia

Question 1

Does the normal Hb range vary with age?

Answer 1

Yes
Anaemia in neonates = <140
1 month to 12 months <100
1 year to 12 years <110

Question 2

What mechanisms does anaemia result from?

Answer 2

Reduced red cell production - ineffective erythropoiesis (iron deficiency is most common) or due to red cell aplasia
Increased red cell destruction (haemolysis)
Blood loss - uncommon in children

Question 3

If there is a combination of the 3 mechanisms of anaemia, what is it called?

Answer 3

Anaemia of prematurity

Question 4

What causes of impaired red cell production are there?

Answer 4

Red cell aplasia:
Parvovirus B19 infection
Congenital - Diamond-Blackfan anaemia
Transient erythroblastopenia of childhood
Rarities- Fanconi anaemia, aplastic anaemia, leukaemia

Ineffective erythropoiesis:
Iron deficiency
Folic acid deficiency 
Chronic inflammation e.g juvenile idiopathic arthritis
Chronic renal failure
Rarities - mylodysplasia, lead poisoning

Question 5

What causes of haemolysis are there?

Answer 5

Red cell membrane disorders - hereditary spherocytosis
Red cell enzyme disorders - G6PD
Haemoglobinopathies - thalassaemias, sickle cell disease
Immune - HDN, autoimmune haemolytic anaemia

Question 6

Blood loss can cause anaemia, what can lead to this?

Answer 6

Chronic GI blood loss e.g Meckel diverticulum

Inherited bleeding disorders - Von Willebrand disease

Question 7

What does red cell aplasia mean?

Answer 7

Complete absence of red cell production

Question 8

What does ineffective erythropoiesis mean?

Answer 8

Red cell production occurs at normal or increased rate, but differentiation and survival of the red cells is defective

Question 9

What diagnostic clues to ineffective erythropoiesis are there?

Answer 9

Normal reticulocyte count

Abnormal MCV - low in iron deficiency, high in folic acid deficiency

Question 10

What are reticulocytes?

Answer 10

Immature RBCs
Appear slightly larger and have a mesh like pattern of RNA that is visible under certain stains
Circulate in blood from approx 1 day before developing into mature RBCs

Question 11

What are the main causes of iron deficiency?

Answer 11

Inadequate intake
Malabsorption
Blood loss

Question 12

Is inadequate intake of iron common in infants?

Answer 12

Yes because additional iron is required for the increase in blood volume accompanying growth and to build up the child’s stores

Question 13

Where can iron come from?

Answer 13

Breastmilk - low iron content, but 50% absorbed
Infant formula - supplemented with iron
Cow’s milk - higher iron content than breastmilk but only 10% absorbed
Solids introduced at weaning e.g cereals

Iron deficiency may develop due to delay in mixed feeding introduction or diet with insufficient iron rich foods, especially if large amount of cow’s milk

Question 14

What vitamin increased iron absorption?

Answer 14

Food rich in vitamin C

Question 15

What inhibits iron absorption?

Answer 15

Tannin in tea

Question 16

Why should infants not be fed up modified cow’s milk?

Answer 16

It’s iron content is low and poorly absorbed

Question 17

Most children are asymptomatic until the Hb drops below…

Answer 17

60-70g/L

Question 18

What symptoms are associated with anaemia?

Answer 18

Tire easily
Young infants feed more slowly
May appear pale
Ask about blood loss and symptoms/signs suggesting malabsorption
Pica - inappropriate eating of non food materials e.g soil, chalk
Might impact behaviour and intellectual function

Question 19

What blood results suggest iron deficiency anaemia?

Answer 19

Hypochromic - low Hb content 
Microcytic - small RBCs 
Low serum ferritin 
Low serum iron 
Increased total iron binding capacity

Question 20

What are the main cause of microcytic anaemia?

Answer 20

Thalassaemia (beta) 
Anaemia of chronic disease - e.g due to chronic kidney disease 
Iron deficiency anaemia
Lead poisoning 
Sidroblastic

Question 21

How is iron deficiency anaemia managed?

Answer 21

Dietary advice

Supplementation with oral iron - Sytron or Niferex

Question 22

How long should iron supplementation be taken for?

Answer 22

Continue until Hb normal then minimum of 3 further months to replenish stores

Question 23

If child does not respond to oral iron, what does this suggest?

Answer 23

Non compliance with treatment

Investigate for other causes especially malabsorption- coeliac disease or chronic blood loss

Question 24

Should a blood transfusion be necessary for dietary iron deficiency anaemia?

Answer 24

No
Even children with deficiency of 20-30g/L due to iron deficiency have arrived at this level over a prolonged period and can tolerate it

Question 25

Some children have low serum ferritin, but have not yet developed anaemia. Should they be treated with oral iron?

Answer 25

Controversial

• iron required for normal brain development
• treatment carries risk of accidental poisoning

Simple strategy: provide dietary advice and offer parents the decision to add oral iron supplementation

Question 26

What should you suspect in recurrent IDA?

Answer 26

Bleeding - Meckel’s diverticulum or oesophagitis