Paeds HAEM Flashcards
In general, which haematological disorders are autosomal dominant vs recessive?
Dominant = generally structural disorders
Recessive = generally metabolic disorders
Which genetic abnormality predisposes women to haemophilia?
Turner’s syndrome
When is haemophilia most likely to present, and with what symptoms?
At ~ 1y, as this is when walking (+ therefore falling) begins
Haemarthrosis
Suspicions of NAI (if no FH)
How does haemophilia present if it presents at neonatal age?
Intracranial haemorrhage
Bleeding circumcision
Prolonged bleeding from venepuncture
Which measures of clotting time are normal vs prolonged in haemophilia?
PT normal
APTT prolonged
(PT is extrinsic, APTT is intrinsic)
In girls, what is the top alternative differential for the same signs and symptoms as haemophilia?
vWD
How should mild haemophilia be managed?
Desmopressin: this stimulates f8 + vWF release
How should severe haemophilia be managed?
Prophylactic factor replacement via Hickman line
How should minor bleeds be managed in haemophilia?
IV infusion of f8/9 concentrate: raise to 30% normal
How should major bleeds be managed in haemophilia?
IV infusion of f8/9 concentrate: raise to 100%, then maintain at 30% for 2w
What is the other name for idiopathic thrombocytopaenic purpura?
Immune TP
In what age group is ITP seen?
2-6y
What is the most common cause of ITP?
Viral infection: ITP presents about 1-2w later
Recall the aetiology of ITP
Immune destruction of platelets by IgG autoantibodies
Directed against glycoprotein IIb/IIIa
Give 3 signs of ITP
Bruising
Petechial or purpuric rash
Bleeding less common- typically presents as epistaxis or gingival bleeding
How should ITP be investigated?
Diagnosis of exclusion: do an FBC + blood smear
How should ITP be managed?
In 80% of children it is acute, benign + self-limiting: will resolve spontaneously within 6-8w
Only treat if evidence of major bleeding or persistent minor bleeding
What advice should be given in ITP management?
Avoid contact sport
Avoid Aspirin + NSAIDs
How should major bleeding in ITP be managed?
IVIG
Corticosteroids: Red
Anti-RhD (if +ve)
What is second line management in ITP for major bleeding?
Rituximab
High dose dexamethasone
How should life-threatening haemorrhage be treated in ITP?
Platelet transfusion (temporary)
Splenectomy
When is ITP considered chronic?
after 6 months persistence
How should chronic ITP be managed?
Mycophenalate mofetil
Rituximab
Eltrombopag (thrombopoeitin agonist)
2nd line = splenectomy
Recall the symptoms of IDA In children
May be asymptomatic
Feeding slowly, tiring quickly, “pica” (eating soil, dirt, etc)
What iron supplement dose is appropriate for children?
Ferrous sulphate 200mg TDS
Upon which chromosome is the beta globin gene found?
Chromosome 11
When does HbA synthesis become predominant?
4-6m
What is the defect in sickle cell anaemia?
Defective beta globin chain
Glutamine to valine on codon 6 on C11
What is the inheritance pattern of SCA?
Autosomal recessive
Recall the genotype that encodes for sickle cell trait?
BB^s
Recall the genotype that encodes for sickle cell anaemia?
B^s B^s
Recall the genotype that encodes for HbC disease
B^c B^s
What is beta thalassaemia?
Redcuced beta globin synthesis
What is the inheritance pattern of beta thalassaemia?
Autosomal recessive
What are the 3 phenotypes of alpha thalassaemia and genotypes?
4 alpha globin deletions = alpha thalassaemia major/ Hb Barts
3 alpha globin deletions = HbH disease
1/2 alpha globin deletions = alpha thalassaemia trait
What is the prognosis of each of the phenotypes of alpha thalassaemia?
Hb Barts = fatal in utero via hydrops fetalis
HbH disease = mild/ mod anaemia
Trait = asymptomatic with mild/ no anaemia
What is the gold standard diagnostic method for both SCD/ thalassaemia?
Electrophoresis
What is the most common early sign of SCD?
Hand + foot syndrome (swollen hands + feet + dactylitis)
What 2 infections are people with SCD particularly at risk of getting?
Pneumococcus + parvovirus
What symptom of SCD only presents in children (not adults)?
Splenomegaly
What screening test should be done in suspected SCD?
Solubility test
What is the gold standard diagnostic method for SCD?
Haemoglobin electrophoresis
What would a blood smear show in SCD?
Sickle cells, Howell-Jolly bodies, nucleated RBCs
What prophylactic medications should be given to people with SCD?
OD oral penicillin
OD oral folic acid
Why is folic acid given in SCD?
Hyperplastic erythropoiesis, growth spurts, increased turnover
How should acute crises be treated in sickle cell disease?
Analgesia
Hydration
Abx
O2
Exchange transfusion
How should the chronic problems of SCD be treated?
Hydroxycarbamide
HSCT in severe cases
Recall the 3 key signs and symptoms of beta thalassaemia major
Extramedullary haematopoiesis
Anaemia
Iron overload
Recall 3 signs of extramedulllary haematopoiesis
Bone expansion
Hepatosplenomegaly
Frontal bossing
Recall the signs of beta thalassaemia trait
Microcytosis: otherwise asymptomatic
What would a blood smear show in thalassaemia?
Microcytic red cells
Tear drop cellls
Microspherocytes
Target cells
Schistocytes
Nucleated RBCs
How should beta thalassaemia major be managed?
Blood transfusion +/-Iron chelation (desferrioxamine/ deferiprone)
Recall 4 signs and symptoms of HDN in the newborn?
Yellow amniotic fluid
Pallor
Jaundice 24-36 hours after birth
Hydrops fetalis (hepatosplenocardiomegaly)
How can HDN be investigated?
Coombe’s test pos
Haemolysis –> raised uBR and reticulocytes
Amniocentesis/ USS (shows organomegaly)
How can HDN be prevented?
Prophylaxis within 72h of a sensitising event
Kleiheur test can determine need for more
If before 20w: 250IU
If after 20w: 500IU
Routine antenatal anti-D prophylaxis is done if necessary, following antibody screen at 28w
Prophylaxis = 2 doses of anti-D
How can HDN be treated?
Phototherapy (uBR)
IV Ig (if BR is rising fast)
If severe or in utero –> transfusion into umbilical vein
Which 6 inborn errors of metabolism are tested for at the newborn blood test screen?
PKU
MCADD
Glutaric Aciduria T1
Isovaleric acidaemia
Homocysteinuria
MSUD
What is the inheritance pattern of those inborn errors of metabolism?
Autosomal recessive
What is the deficiency in PKU?
Phenylalanine hydroxylase
Recall the typical appearance of a child with PKU
Blonde hair, blue eyes, eczema, microcephaly
What are the symptoms of PKU (unmanaged)?
Learning difficulties and seizures
How is PKU managed?
Low phenylalanine diet
Recall the signs and symptoms of MCADD
Encephalopathy within 1w + SIDS
Hypoglycaemia and hypoketonuria
What investigation is done to diagnose MCADD?
Urinalysis: shows absent ketones and medium-chain dicarboxylic aciduria
What is G6PD’s role?
Rate limiting enzyme in the pentose phosphate shunt
What is the inheritance pattern of G6PDD?
X - linked
What are the main signs and symptoms of G6PDD?
Neonatal jaundice
Acute intravascular haemolysis (–> fever, malaise, abdo pain and dark urine)
What type of disease is Gaucher’s disease?
Lysosomal storage disease
What is Gaucher’s disease a deficiency of?
Beta-glucosidase
Which group of people are particularly at risk of getting Gaucher’s?
Ashkenazi Jews
What are the 2 forms of Gaucher’s disease, and their symptoms?
Acute infantile form: hepatosplenomegaly, neurological degeneration with seizures
Chronic childhood form: hepatosplenomegaly and BM suppression (with anaemia)
Which form of Gaucher’s disease is most common?
The chronic childhood form
What would be seen on BM aspirate in Gaucher’s disease?
Gaucher cells
How is Gaucher’s disease managed?
Splenectomy, bisphosphonates (because of BM suppresion), enzyme replacement, treat anaemia
What is the most common form of galactosaemia?
Gal-1-PUT deficiency
Recall the signs and symptoms of galactosaemia
High cBR
Hepatomegaly
Hypoglycaemia
Sepsis (gal-1-phos inhibits the immune response)
How does galactosaemia present if not picked up in infancy?
BL cataracts
How is galactosaemia managed?
Avoidance of galactose
How many types of glycogen storage disease are there?
5
What symptoms are specific to McArdle’s GSD?
Muscle cramps/ weakness after first few mins of exercise, followed by a second ‘wind’ of energy
Recall the symptoms of GSD with the reason behind each one
Hypoglycaemia (G6P cannot leave cells)
Lactic acidosis (G6P builds up as lactate)
Neutropaenia (G6P suppresses the immune system)
How should glycogen storage disease be managed?
Manage intake of CHO carefully to avoid storage
