Paediatric Haematology Flashcards
How does sickle cell disease differ in neonates/children compared to adults?
- Children have red bone marrow in hands/feet - these are additionally susceptible to infarction by sickle cells
- Hence infants can get Hand/foot syndrome - infarction of meta-tarsals in hand/feet
- Occurs in first 2 years of life
- Infants have functioning spleen, so can get SPLENIC SEQUESTRATION (first 3yrs of life)
- Severe anaemia, shock, death
- Older age -> recurrent infarction of spleen -> small fibrotic spleen -> HYPOSPLENISM
- Infants have immature immune system - susceptible to PNEUMOCOCCUS and PARVOVIRUS infection
- 1st exposure to these lead to pure red cell aplasia
- This is problematic in sickle cell children because sickle cells have 10 day lifespan, whereas normal RBCs are 120 days. Hence you get acute anaemia.
- Infants are growing rapidly - Greater need for FOLIC ACID
- Hence on diagnosis infants are started on folic acid for life
- 3 reasons:
- Hyperplastic erythropoeisis requires folic acid
- Growth spurts require folic acid
- Red cell life-span is shorter so can get anaemic very quickly if folic acid deficient
Management principles of sickle cell in infants/child?
- Accurate diagnosis
- Educate parents
- Vaccinate
- Folic acid + Penicillin
Complications of sickle cell more common in children than adults:
- Splenic sequestration
- Red cell aplasia (Pneumococcus, parvovirus)
- Hand-foot syndrome
- Stroke
Siblings with SCA present simultaneously with severe anaemia and low reticulocyte count - likely diagnosis?
Parvovirus B19 first exposure -> Red cell aplasia
6yo Afro-Caribbean boy presents with chest + abdo pain.
Hb 63, MCV 85, blood film shows sickle cells.
Likely diagnosis?
- Sickle cell trait
- Sickle cell anaemia
- Sickle cell/beta thal
Sickle cell anaemia
Not sickle cell trait because you have sickle cells in blood film
Not b-thal because you would have microcytosis - MCV 85 is normal for his age (slightly lower range in children)
When does beta thalassaemia first present?
3-6 months of life
This is when Haemoglobin A production takes over Haemoglobin F in newborn.
Beta globin chain = affects Haemoglobin A production
Types of B-thal
B-thal TRAIT = one B-thal gene
B-thal MAJOR = two B-thal genes
Clinical features of poorly treated B-thal major
- Anaemia -> Heart failure, growth retardation
- Erythropoietic drive -> bone expansion, hepatosplenomegaly
- Iron overload -> Heart failure, gonadal failure
Management of B-thal?
- Accurate diagnosis + Family counselling
- Blood transfusion
- Iron chelation therapy (desferioxamine, deferiprone)
- Consideration of child as an individual and part of a family
Types of inherited haemolytic anaemias in children
- Red cell membrane defects
- Hereditary spherocytosis
- Hereditary elliptocytosis
- Haemoglobin defects
- Sickle cell anaemia
- Glycolytic pathway defect (pathway that provides energy to red cells)
- Pyruvate kinase deficiency
- Pentose shunt defect
- G6PD deficiency
7yo Afro-caribbean boy presents with abdo pain + urinary Sx, was given an anti-emetic by GP
3 days later he presents with jaundice and brought to hospital
WCC 10.9, Hb 58, MCV 100, Pt 275
Likely diagnosis?
- Hep A
- Hep B
- Hereditary spherocytosis
- Sickle cell anaemia
- G6PD deficiency
G6PD deficiency
On blood film you would see irregularly contracted red cells - spleen takes a ‘bite’ out of them.
MCV on upper end of normal due to reticulocytosis as a result of haemolysis
Unlikely to be hereditary spherocytosis or SCA because they would have presented earlier in life
G6PD def - haemolysis can be triggered by INFECTION or oxidant DRUGS - in this case a UTI
What advice do you give to a mother who has G6PD def.?
These things can trigger haemolysis so be aware:
- Infections
- Drugs
- Napthalene
- Fava beans
Epidemiology of G6PD def.?
Prevalent in northern europe/africa - thought to protect against malaria
Caucasians unlikely to have it
X-linked - so males
Examples of acquired haemolytic anaemias?
- Autoimmune haemolytic anaemia
- Malignant - Lymphoma
- Non-malignant - SLE
- HUS (Haemolytic uraemic syndrome)
Examples of common inherited coagulation disorders in children?
- Haemophilia A & B
- Von Willebrand disease
How might haemophilia A/B present?
These would only be in BOYS because factor 8/9 are X-linked
- Bleeding after circumcision
- Haemoarthroses when starting to walk
- Bruises
- Post-traumatic bleeding
Differentials for haemophilia A/B?
- Inherited platelet disorder (thrombocytopenia)
- Acquired coagulation defects
- ITP
- Acute leukemia
- Non-accidental injury (safeguarding)
- Henoch-Schonlein Purpura
- Bleeding into shins
- Coagulation + platelets NORMAL
Investigations for inherited coagulation defects in children?
- History
- Bleeding from umbilical cord or from Guthrie spot
- Haematoma after vaccinations/vitamin K injections
- Bleeding after circumcision?
- FMH (X-linked?)
- Coagulation screen
- Haemophilia A/B = Abnormal APTT (Intrinsic pathway - F8/9)
- Platelet count
- Assays of specific coagulation factors
- F8/9 for Haemophilia A/B
How might Von Willebrand disease present?
- Mucosal bleeding
- Bruises
- Post-traumatic bleeding
Differentials for VWD?
Haemophilia A, because F8 levels are reduced in both
Investigations/Diagnosis for VWD?
- Autosomal dominant so FMH
- Coagulation screen
- Prolonged APTT
- Factor 8 assay
- Platelet aggregation studies
Treatment of VWD?
Low purity F8 concentrates
1yo boy presents with joint bleeding
Hb, WCC, Pt normal
Prolonged APTT, normal PT
Bleeding time normal
Likely diagnosis?
- Haemophilia A
- Haemophilia B
- VWD
- TTP
- Boy took mum’s warfarin tablets
Haemophilia A
Could be either A or B, but A is 5x more common, hence more likely diagnosis.
VWD unlikely as bleeding time is normal
TTP would not give you a coagulation abnormality
Warfarin would prolong PT, not APTT
How would ITP present?
- Petechiae
- Bruises
- Blood blisters in mouth
Investigations for ITP?
- History of febrile illness week or so before
- Blood count + film
Management of ITP?
- Observation
- Corticosteroids
- High dose IVIG
- IV anti-D (if Rh +ve)
