Haematology Flashcards
What are the common causes of iron deficiency anaemia in children?
- Inadequate intake
- Malabsorption
- Blood loss
What are sources of iron for an infant?
- Breastmilk - low content, but 50% is absorbed
- Infant formula
- Cow’s milk - high content, only 10% absorbed
- Solids introduced at weaning (i.e. cereal)
What are the signs and symptoms of iron deficiency anaemia?
- Asymptomatic until <60-70g/L
- Feed slowly
- Tire quickly
- “Pica” = eating soil, dirt, etc.
What are the appropriate investigations for suspected anaemia?
- Microcytic - low MCV
- Hypochromic
- Low ferritin
What is the management of iron deficiency anaemia?
- Dietary advise → dark-green vegetables, meat, apricots, raisins
-
Oral ferrous sulphate, 200mg, TDS until normal Hb + at least 3/12 after
- Monitoring
- Re-check iron levels 2-4w after therapy start (at 3w, Hb should rise 2g/100mL)
- If normal, check at 2-4m (if not, address compliance issues)
- Advise black stools are a common and normal side effect → reduce by eating with food or reduced dose if appropriate
- Monitoring
What are the causes of microcytic anaemia?
TAILS
- Thalassaemia
- Anaemia of Chronic Disease
- Iron deficiency
- Lead poisoning
- Sideroblastic / Congenital
What are the causes of normocytic anaemia?
MR I CALM
- Marrow failure
- Renal failure
- Iron deficiency - early on
- Chronic disease
- Aplastic or Acute blood loss
- Leukaemia
- Myelofibrosis
What are the causes of macrocytic anaemia?
AMHLF
- Alcoholism
- Myelodysplastic syndrome / Multiple myeloma
- Hypothyroidism or Haemolytic
- Liver failure
- Folate / B12 deficiency
What are the signs and symptoms of sickle cell disease?
- Hand and foot syndrome → swollen hands & feet; dactylitis
- Acute chest syndrome (ACS)
- Splenic sequestration → anaemia, shock, death
- Painful crises / vaso-occlusive ± priapism
- Infection (pneumococcus and parvovirus)
- Splenomegaly (only in children)
What are the appropriate investigations for sickle cell disease?
- Family origins questionnaire – Afrocaribean of African descent (some northern Europe)
- Guthrie testing after antenatal screening
- Solubility test - if cloudy → haemoglobin electrophoresis (gold-standard)
- FBC and blood smear
- Sickle cells
- Howell-Jowell bodies (hyposplenism)
- Nucleated RBCs
How does sickle cell disease cause anaemia?
- Haemolysis
- HbS is a low-affinity Hb → more readily releases O2 → reduced EPO-drive → anaemia
What is the management of sickle cell disease?
- Education → minimise trigger exposure for crises (cold, dehydration, excessive exercise, hypoxia)
- Vaccination → immunisation against encapsulated organisms (e.g. Pneumococcus / S. pneumoniae and HiB)
-
Prophylaxis
- OD oral penicillin
- OD oral folic acid (due to hyperplastic erythropoiesis, growth spurts, increased turnover)
- Treatment of Chronic Problems:
- Recurrent ACS or vaso-occlusive crisis = Hydroxycarbamide
- Stimulated HbF production
- Monitor for white blood cell suppression
- HSCT (severe cases)
- Recurrent ACS or vaso-occlusive crisis = Hydroxycarbamide
What are the common triggers for acute crises?
- Cold
- Dehydration
- Excessive exercise
- Hypoxia
What is the prognosis of sickle cell disease?
- Premature death due to complications
- 50% of patients with the most severe form of sickle cell disease will die <40 years
- Aplastic anaemia from B19 infection
What are the signs and symptoms of beta thalassaemia major?
-
Extramedullary haematopoiesis
- Bone expansion
- Hepatosplenomegaly
- Frontal bossing
-
Anaemia (3-6m of age)
- Heart failure
- Growth retardation
-
Iron overload - from transfusions
- Heart failure
- Gonadal failure
What are the signs and symptoms of beta thalassaemia minor?
- Asymptomatic
- Microcytosis with normal/low-normal haemoglobin
What are the appropriate investigations for suspected beta thalassaemia?
- Family origins questionnaire – Indian, Mediterranean, Middle East
- Guthrie testing after antenatal screening
- Haemoglobin electrophoresis = gold-standard
- Blood smear
- Microcytic red cells
- Tear drop cells
- Microspherocytes
- Target cells
- Schistocytes
- Nucleated RBCs
What is the management of thalassaemia?
- Beta thalassaemia major
- Blood transfusion ± iron chelation (desferrioxamine, deferiprone)
- HSCT - only for children with an HLA-identical sibling
- Beta thalassaemia minor = No treatment necessary
What is the management of an acute crises in sickle cell disease?
- Analgesia - avoid morphine <12 years
- O2
- Hydration
- Exchange transfusion - ACS, priapism, stroke
- Antibiotics - if infection
What is G6PD?
Rate-limiting enzyme in the pentose-phosphate shunt which is vital to prevent oxidative damage to RBCs.
What are the risk factors for G6PDD?
- Ethnicity = Central Africa, Mediterranean, Middle East, Far East
- X-linked
- Males
- Homozygous females
- ‘Lionised’ females → random X-chromosomes inactivated
What are the signs and symptoms of G6PDD?
- Neonatal jaundice - most common cause requiring transfusion
- Acute intravascular haemolysis
- Fever
- Malaise
- Abdominal pain
- Dark urine
- Asymptomatic outside of these events
What are the causes of acute intravascular haemolysis in G6PDD?
- Infection
- Drugs
- Antimalarials (i.e. quinine)
- Analgesics (i.e. high-dose aspirin)
- Antibiotics (i.e. nitrofurantoin)
- Fava/broad beans
- Mothballs/Insect repellent
What are the appropriate investigations for suspected G6PDD?
- Nothing abnormal between acute episodes
- G6PD
- Raised during an acute episode – higher enzyme concentration in reticulocytes
- Reduced after the acute episode
- Confirm via G6PD in acute setting and 1 month after
- Blood film (acute) → Heinz bodies, bite cells
What is the management of G6PDD?
- Advice to be aware of signs of acute haemolysis → jaundice, pallor, dark urine
- Avoidance of specific drugs, chemicals and foods
- Acute haemolysis → supportive care + folic acid
- Blood transfusion rarely required
Define Haemolytic Disease of the Newborn.
Maternal antibodies against foetal blood group antigens.
- Maternal antibodies cross placenta / mix at delivery → haemolysis
- Mother must have been sensitised for this to happen → from secondary pregnancy onwards
What are the signs and symptoms of haemolytic disease of the newborn?
- Yellow amniotic fluid
- Hydrops fetalis - hepatosplenocardiomegaly
- Pallor
- Jaundice 24-36 hours after birth (<2 days)
What are the appropriate investigations for suspected haemolytic disease of the newborn?
- Coombe’s test (DAT) +ve
- Haemolysis = raised uBR and reticulocyte count
- Amniocentesis
- USS = organomegaly
What is the management of haemolytic disease of the newborn?
- Prevention
-
Prophylaxis after sensitising events <72hrs - Kleiheur test can determine need for more
- 250 IU before 20 weeks
- 500 IU after 20 weeks
-
Routine Antenatal Anti-D Prophylaxis (identified from antibody screen at 28 weeks
- 2 doses of 500 IU at 28 and 34 weeks OR
- 1 dose of 1500 IU at 28 weeks and Foetal cord gas post-delivery and prophylaxis → <72 hours (500 IU anti-D) if baby +ve Kleiheur
-
Prophylaxis after sensitising events <72hrs - Kleiheur test can determine need for more
- Treatment
- Jaundice = Phototherapy and IVIG - if bilirubin is rising >8.5 umol/L/hr
- Severe or in utero = Transfusion into umbilical vein → delivery 37-38w
Define Idiopathic Thrombocytopaenic Purpura.
Immune destruction of platelets by IgG autoantibodies.
- Same as Immune TP - new terminology
What is the most common cause of thrombocytopaenia in children?
ITP - usually between 2-6yo
What are the signs and symptoms of ITP?
- Short history (days-weeks) of
- Petechiae / Purpura
- Superficial bruising
- Epistaxis and other mucosal bleeding
- Often presents much more acutely than in adults
- Recent history (1-2 weeks) of a viral infection
- Intracranial bleeding - rare → 0.1-0.5%
What are the appropriate investigations for suspected ITP?
-
Diagnosis of exclusion → exclude genetic and leukaemia/cancer causes
- FBC
- Blood smear
- Genetic analysis
What is the management of ITP?
- Asymptomatic or Minor Bleeding (plts >20 x109/L) = Self-limiting → observation
- Major Bleeding (plts <20 x109/L) = IVIG + corticosteroids ± anti-RhD
- Life-threatening haemorrhage = Platelet transfusion - raises platelets for a few hours
What is the management of chronic ITP?
Platelets remain low 6/12 after diagnosis
- 1st line
- Mycophenolate mofetil
- Rituximab
- Eltrombopag (thrombopoietin agonist)
- 2nd line
- Splenectomy
What is Haemophilia?
- Deficiency of factors in the intrinsic pathway leading to APTT prolongation
- Factor VIII = A
- Factor IX = B
- X-linked recessive - primarily affecting males
- A: 1 in 10,000
- B = 1 in 50,000
- If a female is affected, it is likely they have Turner’s syndrome (only 1 X chromosome)
What are the signs and symptoms of haemophilia?
- Presenting around 1yo
-
Heamarthrosis → leading to arthritis
- Present when walking begins and therefore so does falling over
- Suspicions of NAI (if no FHx)
-
Heamarthrosis → leading to arthritis
- Presenting at neonatal age (40%):
- Intracranial haemorrhage
- Bleeding circumcision
- Prolonged bleeding from venepuncture
What are the appropriate investigations for suspected haemophilia?
- Neonate history of bleeding from Vit-K injection, umbilical cord separation, circumcision
- FHx
- Clotting studies
- Extrinsic = normal PT/INR
- Intrinsic = prolonged APTT
- Platelet count
- Factor 8 levels
- F8 is low in vWD - always consider vWD especially in girls
What is the management of haemophilia?
- Mild haemophilia A = Desmopressin - stimulates F8 and VWF release
- Severe haemophilia = Prophylactic factor replacement
- Can be done at home
- Begins at 2-3yo, 2-3x/week
- Raise baseline to above 2%
- If actively bleeding
-
IV infusion of F8/9 concentrate
- Minor bleeds = raise to 30% normal to treat minor/simple bleeds
- Major bleeds = raise to 100%; maintain at 30% for 2/52 to prevent secondary haemorrhage
-
IV infusion of F8/9 concentrate
- Avoid
- IM injections
- Aspirin
- NSAIDs
What are the complications of haemophilia?
- Chronic arthropathy
- Compartment syndrome
- Haematuria
- HBV → transfusion-related
What is Gaucher’s disease?
The most common lysosomal storage disease → beta-glucosidase deficiency.
- Pompe’s disease = Alpha glucosidase
- Fabry disease = Alpha-galactosidase A defect
- Niemann-Pick Disease type C = Cholesterol trafficking disorder
- Wolman disease = Lysosomal acid lipase defect
What inheritance patterns does Gaucher’s disease follow?
-
Autosomal recessive
- Carrier rate of 1 in 100 → 1 in 40,000 births
- 1 in 100 carrier rates → 2 carriers meeting and having a child = 0.01% chance
- Child homozygous = 25% → 0.0025% chance (100/0.0025 = 1 in 40,000 affected)
- Carrier rate of 1 in 100 → 1 in 40,000 births
- Ashkenazi Jew carrier rate 1 in 10 → 1 in 500 births
What diseases are more common in Ashkenazi Jews?
- Gaucher’s disease
-
Tay-Sachs disease (hexosaminidase A deficiency)
- S/S = deaf, blind, progressive neurodegeneration
- Inflammatory bowel disease
What are the signs and symptoms of Gaucher’s disease?
- Acute infantile form
- Hepatosplenomegaly
- Neurological degeneration with seizures
- Chronic childhood form (most common):
- Hepatosplenomegaly
- BM suppression → anaemia, immunodeficiency, clotting issues
What are the appropriate investigations for Gaucher’s disease?
- FBC
- Blood film
- LFTs and clotting
- USS of liver and spleen
- BM aspirate → Gaucher cells
What is management of Gaucher’s disease?
- Splenectomy
- Bisphosphonates
- Enzyme replacement - IV recombinant glucocerebrosidase
- Anaemia treatment
What is Galactosaemia?
- Are 3 forms of galactosaemia → most common is Galactose-1-Phosphate Uridyl Transferase deficiency
What are the signs and symptoms of galactosaemia?
- Jaundice
- Hepatomegaly
- Hypoglycaemia
- Sepsis - gal-1-phos inhibits the immune response
- Not picked up in infancy → present in early life with bilateral cataracts
What are the appropriate investigations for galactosaemia?
- High galactose in urine
- Red cell Gal-1-PUT
What is the management of galactosaemia?
Avoid galactose
What are Glycogen Storage Diseases?
- Type 1 = von Gierke’s → glucose-6-phosphatase deficiency
- Glucose can’t be liberated from glucose-6-phosphate so builds up inside cells as G6-phosphotase is used to remove the high-energy phosphate group so the glucose can leave the cell
- Type 2 = Pompe’s → a-glucosidase deficiency
- Type 3 = Cori’s / Forbe’s → amylo-1, 6-glucosidase deficiency
- Type 4 = Anderson’s → 1, 4-a-glucan branching enzyme deficiency
- Type 5 = McArdle’s → myophosphorylase deficiency
- Muscle cramps / weakness after first few minutes of exercise → ‘second wind’ of energy
What are the signs and symptoms of glycogen storage disease?
- Hypoglycaemia → G6P cannot leave cells
- Lactic acidosis → G6P builds up as lactate
- Neutropenia → G6P supresses the immune system
- Hepatomegaly
- Nephromegaly