Anaemia

Question 1

Describe the normal Hb changes in children

Answer 1

Hb normally falls during the first months of life, reaching a low point at 6-8 weeks old, and spontaneously coming back up by 4 months. Infants are usually born with adequate iron stores to last the first 3-4 months of life, so true iron-deficiency below 4 months, in the absence of blood loss (e.g. gastrointestinal), is rare.

Question 2

What are the causes of anaemia in children

Answer 2

Microcytic: IDA, thalassaemia, SCD
Normocytic: Haemolytic anaemia, SCD, aplastic anaemia, ACD
Macrocytic: Vit B12 or folate deficiency

Question 3

What are the causes of iron deficiency anaemia

Answer 3

Bleeding e.g. menstrual/GI
Increased use e.g. growth/pregnancy, malignancy
Dietary deficiency e.g. vegetarian
Malabsorption e.g. coeliac, IBD
Adolescent pregnancy
Early cow’s milk introduction
Lack of delayed cord clamping at birth

Question 4

What are the sources of iron in neonates

Answer 4

Breast milk (50%)
Formula
Cow’s milk (poor source)
Solids at weaning

Iron in breast milk is well absorbed but the iron in artificial feeds or cow’s milk is less so

Question 5

What are the signs and symptoms of iron deficiency anaemia

Answer 5

Lethargy/fatigue/difficulty concentrating
Light-headedness/dizziness
SOB
Irritability/poor feeding
Pallor
Brittle nails and hair
Koilonychia
Cheilitis, angular stomatitis
Glossitis

Question 6

What investigations should be done for iron deficiency in children

Answer 6

FBC: microcytic anaemia
Iron studies:
- Serum iron - Reduced in IDA
- Iron binding capacity - Raised in IDA
- Serum ferritin - Reduced in IDA, raised in sideroblastic
- Transferrin - Reduce in IDA
Film: microcytic, hypochromic RBC, anisocytosis, poikilocytosis, target cells, pencil cells, elliptocytes

Question 7

What is the management plan for iron deficiency in children

Answer 7

1. exclude underlying causes
2. Diet and advice (green leafy vegetables, vit C, avoid milk/tea/high fibre)
3. Iron supplementation for 3 months (Sytron)

± Oral folic acid if the cause is not known (can exacerbate B12 deficiency symptoms if given)
± IM hydroxocobalamin for B12 deficiency

Second line: parenteral iron

Question 8

What are the complications and prognosis of anaemia in children

Answer 8

Preterm or LBW (Low Birth Weight) baby
Postpartum depression
Child with developmental delays
Spina bifida
Susceptibility to infections
Physical weakness
Postpartum haemorrhage
Increased risk of neonatal iron deficiency

Good prognosis

Question 9

Define thalassaemia

Answer 9

Group of genetic disorders characterised by a defect in and reduced globin chain synthesis

Alpha or beta

Question 10

What is the aetiology of alpha thalassaemia and what are the types

Answer 10

Alpha-globin gene mutation on Chr 16

1-2 gene deletion: Microcytic hypochromic red cells, no anaemia - Alpha (+)
3 gene deletion: Microcytic hypochromic anaemia, splenomegaly (Hb H)
4 gene deletion: Hb Barts and intrauterine death (hydrops fetalis) - Alpha (0)

Question 11

What is the aetiology of beta thalassaemia and what are the types

Answer 11

Beta-globin gene mutation on Chr 11
Autosomal recessive inheritance

Trait → Carrier, asymptomatic, mild microcytic anaemia, raised RBC
HbE beta
Thalassaemia Intermedia → Mild defect in synthesis (+ forms instead of 0) → reduced alpha chains or increased gamma chains
Thalassaemia Major → No globin production, homozygous, both copies affected, B0/B+

Question 12

What are the symptoms of thalassaemia

Answer 12

Anaemia: Fatigue, Pallor, Dizziness, SOB

Alpha
Alpha (+): asymptomatic
Alpha HbH: variable, anaemia symptoms, jaundice, gallstone symptoms

Beta
- Presents at 3-6 months (due to switch form gamma (HbF) to beta globin (HbA) synthesis)
- Failure to thrive and prone to infections
- Anaemia → heart failure, growth retardation, Dyspnoea, fatigue
- Erythropoietic drive (extra-medullary haematopoiesis)→ bone expansion, hepatomegaly (facial and small bones), splenomegaly
- Iron overload → heart failure, gonadal failure

Question 13

What are the signs of thalassaemia on examination

Answer 13

Facial dysmorphism: skull bossing, maxillary overgrowth
Poor growth
Mild jaundice
Pallor
Hepatosplenomegaly

Question 14

What investigations should be done for thalassaemia

Answer 14

Heel prick at 5 days

Bloods:
- FBC: microcytic anaemia
- Reticulocytes: elevated
- Iron studies: normal
- Blood film: microcytic, hypochromic RBCs, poikilocytosis, Howell Jolly bodies (nucleated RBCs), Target cells
- Beta major: Alpha globin precipitates and Pappenheimer bodies
- Perl’s stain: inky blue granules (haemosiderine/pappenheimer bodies)
Hb electrophoresis: Raised HbA2 and HbF, Absent or reduced HbA
LFTs: elevated total/unconjug bilirubin

Bone marrow: erythroid hyperplasia, hypercellular

Question 15

What is the management for thalassaemia

Answer 15

Regular blood transfusions (2-3 units per month)
Iron chelation therapy + audiology and opthalmology screening
Splenectomy + Prophylaxis (immunisation and Abx)
Supportive medical care
Hormone therapy
Hydroxyurea to boost HbF
Bone marrow transplant
± Accurate diagnosis and family counselling

Question 16

What are the complications of thalassaemia

Answer 16

Cholelithiasis and biliary sepsis (gall stone formation)
Cardiac failure (leading cause of death)
Endocrinopathies
Liver failure
Increased risk of infection

Question 17

What is the prognosis for thalassaemia

Answer 17

Alpha
Trait: asymptomatic → genetic counselling
HbH: normal life
Hb Bart: survival into childhood, risk of congenital anomalies, neuro impairment, lifelong transfusion + support

Beta
Intermedia: cosmetic changes
Major: fatal untreated, near-normal if treated

Question 18

What are the causes of vitamin B12 deficiency

Answer 18

Dietary (e.g. vegans) - B12 found in meat and dairy
Malabsorption:
- Stomach (lack of intrinsic factor which is produced by gastric parietal cells) → Pernicious anaemia, post gastrectomy
- Terminal ileum (absorption) due to ileal resection, Crohn’s disease, bacterial overgrowth, tropical sprue and tapeworms.

Question 19

What are the clinical features of B12 deficiency

Answer 19

Mouth: Glossitis, angular cheilosis
Neuropsychiatric: Irritability, depression, psychosis, dementia.
Neurological: Paraesthesiae, peripheral neuropathy (loss of vibration and proprioception first, absent ankle reflex, spastic paraperesis, subacute combined degeneration of spinal
cord)

Question 20

What is pernicious anaemia and what investigations should be done for diagnosis

Answer 20

Autoimmune atrophic gastritis → achlorhydria and lack of gastric intrinsic factor
Most common cause of a macrocytic anaemia in Western countries (Usually >40yrs)
Specific tests: Parietal cell antibodies (90%), Intrinsic factor antibodies (50%), Schilling qtest (outdated)

Question 21

What are the causes of folate deficiency

Answer 21

Poor diet
Increased demand: pregnancy or ↑ cell turnover (haemolysis, malignancy, inflammatory disease and renal dialysis).
Malabsorption: coeliac disease, tropical sprue.
Drugs: alcohol, anti-epileptics (phenytoin), methotrexate, trimethoprim

Question 22

What is the management for B12 and folate deficiencies

Answer 22

B12: Replenish stores with IM hydroxocobalamin (B12) with 6 injections over 2 weeks. (if pernicious anaemia → 3-monthly IM injection)

Folate: oral folic acid (B12 is checked and replaced prior to folic acid otherwise folic acid may exacerbate the neuropathy of B12 deficiency)

Question 23

What are the complications of B12 deficiency

Answer 23

Subacute degeneration of the cord (Dorsla columns)
S/S: tingling, numbness, weakness, visual impairment, change in mental state, bilateral paresis/paralysis