Haematology and Oncology Flashcards
How is childhood anaemia defined?
<11g/dL in children 6 months to 5 years
<11.5g/dL in children 5 to 11 years
<12g/dL in children 12 years and over
What is the most common cause of anaemia in children?
Iron deficiency anaemia - due to rapid growth and diet
In which ethnic groups is sickle cell disease seen more frequently?
Central Africa
In which ethnic groups is beta thalassaemia seen more frequently?
SE Asia
Mediterranean
Middle Eastern
How can the causes of anaemia be classified?
- Reduced Hb/RBC production
- Increased RBC destruction/haemolysis
- Blood loss
Give three causes of anaemia due to reduced RBC/Hb production?
Bone marrow aplasia Bone marrow replacement by tumour cells Bone marrow replacement by fibrous tissue/granulomas Iron deficiency B12 deficiency/pernicious anaemia Folate deficiency Thalassaemias
Give two examples of bone marrow aplasia
Fanconi’s anaemia (congenital aplastic anaemia)
Diamond-blackfan anaemia (red blood cell aplasia)
Which conditions cause bone marrow replacement by:
(i) tumour cells?
(ii) fibrous tissue/granulomas?
i. Leukaemias, secondary mets
ii. TORCH infections
Why might a child become deficient in:
(i) folic acid?
(ii) B12?
i. rapid growth, malabsorption (coeliac)
ii. breast feeding from vegetarian mother, malabsorption (coeliac)
What can cause anaemia due to haemolysis?
Genetic causes:
RBC membrane defects - hereditary spherocytosis
RBC enzyme abnormalities - G6PDD
Haemoglobinopathies - sickle cells disease, thalassaemias
Acquired causes:
Isoimmune haemolysis - HDoN, blood transfusion reactions
Infections, drugs and toxins
What does the reticulocyte count show?
Low in iron deficiency
Increased in haemolysis/blood loss
What are the markers of iron deficiency?
Low reticulocytes
Low MCV
Low ferritin
Pale and small - HypOchromic and micrOcytic cells
Who is iron deficiency more commonly seen in?
Preterm babies
Twins
Infants fed mainly on cows milk/late weaners
Social deprivation/poverty: Less red meat, green veg, eggs and bread
Chronic malabsorption (coeliac)
Adolescent girls - rapid growth, menstruation
Pica
What is pica?
When children eat almost anything, including soil or dirt
Latin name for magpie
Can cause lead poisoning if paint is ingested
What signs might be apparent on clinical examination in a child with anaemia?
Growth/FTT Angular cheilosis Koilonychia Jaundice (haemolysis) Clubbing (chronic illness) Lymphadenopathy, hepatosplenomegaly, brusing (leukaemia) Abdominal distension (coeliac) Exertional tachycardia Pale conjunctiva SOB Fatigue/Irritability
What dysmorphic features might be apparent in a child with Fanconi’s anaema?
Short stature Microcephaly Frontal bossing Absent thumbs Hyperpigmented skin
In what case of anaemia would jaundice be present?
Haemolysis
What signs of anaemia might you see in a child with leukaemia?
Lymphadenopathy
Hepatosplenomegaly
Brusing
What type of cells are seen in G6PDD?
Ghost or bite cells
When might you carry out red cell enzyme studies?
If suspecting G6PDD or pyruvate kinase deficiency
Which anameia does Coombs test identify?
Autoimmune haemolytic anaemia
How is iron deficiency anaemia managed?
Sytron (iron supplements) for 3 months
Transfusion (if severe)
When would a child with anaemia require transfusion?
High-output cardiac failure
What mode of inheritance is hereditary spherocytosis?
Autosomal dominant
What mode of inheritance is G6PDD?
X-linked recessive
Which type of anaemia does lead poisoning cause?
Microcytic anaemia
What mode of inheritance is sickle cell disease?
Autosomal recessive
In SCD, where does the mutation occur?
Beta globin gene
What does the presence of sickle cells cause disease?
They have a reduced deformability and are easily destroyed
This causes occlusion of microcirculation and a chronic haemolytic anaemia of about 90g/dL
What are the different types of sickle cell disease?
HbSS/sickle cell anaemia - severe phenotype
HbS /beta0 thalassaemia -
severe, indistinguishable from HbSS
HbSC disease - HbS and HbC - intermediate severity
HbS/ beta+ thalassaemia - mild/moderate severity
HbS /hereditary persistence of fetal Hb - symptom free
What are the typical Hb proportions in sickle cell trait?
60% HbA and 40% HbS
What does sickle cell trait protect against?
Malaria
Where is SCT most prevalent?
Sub-Saharan Africa
What are the clinical features of SCT?
Generally asymptomatic - often have no abnormal clinical findings
Give three potential complications of SCT
Haematuria Decreased ability to concentrate urine Renal papillary necrosis Renal medullary cancer Splenic infarction Exertional rhabdomyolysis Sudden death: induced by hypoxia, dehydration or exercise
Which investigation is usually abnormal in SC trait?
Electrophoresis shows Hb AS
How should you advise a parent of a child with SCT?
Keep them adequately hydrated
Avoid fluid loss and severe heat to prevent complications
When do symptoms usually begin in children with SCD?
3 - 6 months of age - HbF levels begin to fall
Why are kids with SCD more susceptible to infection?
Acute splenic sequestration
How does a child with SCD clinically present?
Anaemic Jaundice Pallor Lethargy Growth restirction/FTT General weakness Delayed puberty Splenomegaly
How does SCD usually cause anaemia?
- Acute splenic sequestration
- Transient red cell aplasia
- Hyperhaemolysis in patients with severe infection
What are the different types of sickle cell crises?
Vaso-occlusive crisis
Aplastic crisis
Sequestration crisis
Acute chest syndrome
What is an aplastic crisis?
Cessation of erythropoiesis cause severe anaemia
What often precipitates an aplastic crisis?
Parvovirus B19 infection
How might kids in aplastic crisis present?
Congestive cardiac failure
What might kids in aplastic crisis need?
Transfusion
What happens in a vaso-occlusive crisis?
There is obstruction of the microcirculation by sickle cells, causing ischaemia
What usually precipitates a vaso-occlusive crisis?
Cold
Infection
Dehydration
How might a child with a vaso-occlusive crisis present?
Pain - loin pain/abdominal pain/swollen painful joints
Tachypnoea
Fits and focal neurological signs
Retinal occlusion
What can happen if the vaso-occlusive crisis involves large vessels?
Thrombotic stroke
Acute sickle chest syndrome
Placental infarction
Why might a child in vaso-occlusive crisis get abdominal pain?
Mesenteric sickling
Bowel ischaemia
Why might a child in vaso-occlusive crisis get loin pain?
Which other symptoms might accompany this?
Renal papillary necrosis
Haematuria
What is a sequestration crisis?
Sequestration crises results from trapping of large amounts of red cells in the spleen and sometimes in the liver
Who does a sequestration crisis more commonly occur in?
Babies and infants
What is acute chest syndrome?
What is its clinical presentation?
Vaso-occlusive crisis affecting the lungs
Characterised by pleuritic chest pain, fever and new pulmonary infiltrate on CXR
What is the most common crisis in kids with SCD?
Vaso-occlusive crisis
2nd most common reason for admission is acute chest syndrome
How is a painful crisis usually managed?
Analgesia
Fluids
Warmth
Rest
Avoid cold exposure
Look for cause e.g. infection and treat
Which drug can be used to reduce the frequency of crisis occurrence|?
Hydroxycarbamide
When are children with SCD given prophylactic penicillin?
By 3 months of age
Which infection are children with SCD more likely to get and specifically vaccinated against?
Pneumococcal
What is the management of acute chest syndrome?
CPAP
Exchange transfusion
Antibiotics - macrolide + IV cephalosporin
What investigation is done to monitor stroke in children with SCD?
Transcranial doppler USS
What other potential complication in kids with SCD requires immediate management?
Priapism (sustained erection) - hydration, analgesia, adrenaline and etilefrine
Give three other complications of SCD
Priapism Chronic pain Nocturnal enuresis Infection Stroke Cor pulmonale Gallstones Retinopathy Chronic leg ulcers Avascular necrosis of femoral/humeral head CKD Learning difficulties
How is diagnosis of sickle cell crisis made?
Positive sickling test wit HbS on electrophoresis
When would you urgently refer a child with SCD to hospital?
Severe pain Dehydration Severe sepsis Acute chest syndrome Neurological signs Symptoms/signs of acute fall in Hb Acute enlargement of spleen Jaundice Haematuria Priapism lasting more than 2 hours or worsening
What mode of inheritance are thalassaemias?
Autosomal recessive
What is the difference between thalassaemia minor and major?
Minor - heterozygous state - thalassaemia trait
Those with the trait are suually asymptomatic or have mild microcytic anaemia
Major - homozygous state - disease
When does thalassaemia present?
Alpha: at birth there are symptoms of haemolytic anaemia (eg, pallor and hepatosplenomegaly)
Beta: usually in the latter part of the first year of life but can be as late as 5 years old because of delay in stopping HbF production
How does thalassaemia usually appear on FBC?
Microcytic hypochromic anaemia Low Hb Low MCV Low MCH Raised iron and ferritin
Which other clinical signs can be seen in thalassaemia?
Hepatosplenomegaly Bone deformities e.g. frontal bossing, prominent facial bones, dental malocclusion Marked pallor Mild-moderate jaundice Exercse intolerance Cardiac flow murmur HF secondary to anaemia FTT/growth restriction
What are the main complications of alpha thalassaemia?
Hydrops fetalis
Perinatal death
What is done to prevent iron overload in thalassaemia patients?
Desferrioxamine bu subcutaneous infusion
What is doen to support RBC production in thalassaemia patients?
Folic acid and Vit C supplements
Regular blood transfusions
Give three complications of thalassaemia
Iron overload (therefore endocrine dysfunction) Transfusion risks Osteoporosis Gall stones/gout Hepatocellular carcinoma
What is the prognosis for severe beta thalassaemia?
80% die within five years
What is HSP?
IgA mediated autoimmune hypersensitivity vasculitis
Who is HSP more common in?
Female
Caucasians
4-6 years old
Which four organs does HSP involve?
Skin
Joints
Gut
Kidneys
What are the risk factors for HSP?
Infection: Group A strep, mycoplasma, EBV
Vaccinations
Environmental factors: allergens, pesticides, cold, insect bites
How does HSP present?
Winter months following URTI Low grade fever Purpuric rash - gravity-dependent Abdominal pain/vomiting/bloody diarrhoea Swollen tender knees/ankles Renal injury - haematuria Scrotal pain (mimics testicular torsion) Headaches Intussusception
How does the HSP rash develop?
Symmetrical erythematous macular rash on back of legs, buttocks and ulnar side of arms
Evolves into raised purpuric lesions that may coalesce and resemble bruises
How is HSP diagnosed?
What do investigations show?
Clinical diagnosis
Urinalysis: haem/proteinuria Raised WCC with eosinophilia Raised ESR Raised Cr Raised IgA Autoantibody screen Abdmonal US/braium enema for ?obstruction Renal biopsy
What are the renal complications of HSP?
Renal involvement is serious in 10%
ESKD (<1%)
Nephrotic syndrome
Oliguria
Hypertension
How should HSP be managed?
HSP is self-limiting, so supportive
NSAIDs for joint pain, but not in renal insufficiency
Steroids/Azathioprine/Cyclophosphamide/Plasmapheresis in renal disease
Corticosteroids for arthralgia and intestinal dysfunction
Plasma exchange (for rapidly progressive nephritis)
How should HSP patients with renal involvement be followed up?
If proteinuria, monthly
No proteinuria - regular blood pressure checking and urinalysis
What are the other complications of HSP?
MI Pulmonary haemorrhage Pleural effusion Intussusception GI bleed Bowel infarction Seizures Mononeuropathies
What is the prognosis for HSP?
Usually resolves but 1 in 4 will recur
The older you present, the worse the course and renal involvement
Younger than 3 years have a shoter, milder course with fewer recurrences
Prognosis largely depends on degree of renal involvement
What is deficient in Haemophilia A and B?
A - Factor VIII
B - Factor IX
Which haemophilia is:
- more common?
- more severe?
A
What is the mode of inheritance of haemophilia?
X-linked recessive
