Paediatrics - Haematology, oncology and immunology Flashcards
what are causes of anaemia in infancy
physiologic anaemia of infancy
anaemia of prematurity
blood loss
haemolysis
twin twin transfusion
haemolytic disease of the newborn
hereditary spherocytosis
G6PD deficiency
what is physiological anaemia of infancy
there is a normal dip in a hemoglobin around 6 to 9 weeks of age in healthy term babies
this is caused by high oxygen delivery due to high haemoglobin at birth causing negative feedback and reduced production of EPO by the kidneys, reducing haemoglobin production
what are causes of anaemia of prematurity
less time in utero receiving iron from the mother
red blood cell creation cannot keep up with rapid growth in the first few weeks
reduced erythropoietin levels
blood tests remove a significant portion of their circulating volume
what is haemolytic disease of the newborn
haemolysis and jaundice in the neonate due to incompatibility between the rhesus antigens on the surface of the red blood cells of the mother and fetus
what test can be done to check for immune haemolytic anaemia
a direct Coombs test - will be positive
what are key causes of anaemia in older children
iron deficiency anemia - normally secondary to dietary insufficiency
blood loss - mentruation in older girls
what are rarer causes on anaemia in children
sickle cell anaemia
thalassemia
leukaemia
hereditary spherocytosis
hereditary elliptocytosis
sideroblastic anaemia
what is a common cause of blood loss causing chronic anaemia particularly in developing countries
helminth infection - roundworms, hookworms and whipworms
what are causes of microcytic anaemia
TAILS
thalassemia
anaemia of chronic disease
iron deficiency anemia
lead poisoning
sideroblastic anaemia
what are causes of normocytic anaemia
3 As and 2 Hs
Acute blood loss
Anaemia of chronic disease
aplastic anaemia
Haemolytic anaemia
hypothyroidism
what are causes of megaloblastic macrocytic anaemia
B12 deficiency
folate deficiency
what are causes of normoblastic macrocytic anaemia
alcohol
reticulocytosis
hypothyroidism
liver disease
drugs such as azathioprine
what are symptoms of anaemia
tiredness
shortness of breath
headaches
dizziness
palpitations
worsening of other conditions
what are symptoms specific of iron deficiency anemia
Pica - dietary craving of non food items
hair loss
what are signs of anaemia
pale skin
conjunctival pallor
tachycardia
raised respiratory rate
what are signs specific to iron deficiency anaemia
koilonychia - spoon shaped nails
angular chelitis
atrophic glossitis - atrophy of papillae
brittle hair and nails
what investigations are done for anaemia
full blood count
blood film
reticulocyte count - high level indicates active production of RBC w
ferritin
B12 and folate
bilirubin
direct coombs test
haemoglobin electrophoresis
what does a high reticulocyte count infer about the type of anaemia present
if there is a high reticulocyte count it shows that there is active production of red blood cells to replace lost cells, which normally indicates the anaemia is due to haemolysis or blood loss
what type of leukaemia is most common in children
acute lymphoblastic leukaemia
what age is the peak of ALL development
2-3 years
what are risk factors for developing leukaemia in childhood
radiation exposure
downs syndrome
kleinfelter syndrome
nonnan syndrome
fanconis anaemia
how does leukaemia present
persistent fatigue
unexplained fever
failure to thrive
weight loss
night sweats
pallor
petechiae and abnormal bruising
unexplained bleeding
abdominal pain
generalised lymphadenopathy
unexplained or persistent bone or joint pain
hepatosplenomegaly
how is leukaemia diagnosed in children
NICE recommends referral of any child with unexplained petechiae or hepatomegaly
urgent full blood count within 48 hours
blood film - shows blast cells
bone marrow biopsy
lymph node biopsy
chest XR
CT
genetic analysis and immunophenotyping
how is leukaemia managed in childhood
paediatric oncology and MDT
- chemotherapy
- radiotherapy
- bone marrow transplant
- surgery
what are complications of chemotherapy
failure to treat the leukaemia
stunted growth and development
immunodeficiency and infections
neurotoxicity
infertility
secondary malignancy
cardiotoxicity
what is the prognosis of ALL in children
overall cure rate is around 80%
what is immune thrombocytopenia (ITP)
condition characterised by spontaneous low platelet count causing a purpuric rash due to immune dysregulation
what type of immune reaction is ITP
type II hypersensitivity reaction - production of antibodies that target and destroy platelets
how does ITP present
usually presents in children under 10
often there is history of a recent viral illness
bleeding - from gums, epistaxis or menorrhagia
bruising
petechial or purpuric rash caused by bleeding under the skin (non blanching)
how is ITP diagnosed
condition is diagnosed by doing an urgent full blood count for the platelet count
exclude other causes of low platelet count
what is the management of ITP
dependent on how low the platelet count is
usually no treatment is required and patients are monitored until platelets return to normal
if severe thrombocytopenia or the patient is actively bleeding then give: prednisolone, IV immunoglobulins, blood transfusions and platelet transfusions (temporary)
why do platelet transfusions only work temporarily in ITP
because the antibodies against platelets will begin destroying the transfused platelets as soon as they are infused
what advice should be given to someone with a diagnoses of ITP
Avoid contact sports
Avoid intramuscular injections and procedures such as lumbar punctures
Avoid NSAIDs, aspirin and blood thinning medications
Advice on managing nosebleeds
Seek help after any injury that may cause internal bleeding, for example car accidents or head injuries
what are complications of ITP
Chronic ITP
Anaemia
Intracranial and subarachnoid haemorrhage
Gastrointestinal bleeding
what is the pathophysiology of sickle cell anaemia
during foetal development fetal haemoglobin production decreases around 32-36 weeks and adult haemoglobin increases. There is a transition from HbF to HbA, and by 6 months of age there is very little HbF.
Patients with sickle cell disease have an abnormal variant called HbS which results in the sickling of red blood cells
what is the inheritance pattern of sickle cell disease and the genetic mutation that causes it
autosomal recessive
caused by a point mutation in the beta haemoglobin gene on chromosome 11
what is the link between sickle cell and malaria
sickle cell disease is more common in areas traditionally affected by malaria such as Africa, India, the Middle east and the Caribbean.
having sickle cell trait reduces the severity of malaria
when is sickle cell screened for in the UK
newborn spot test at around 5 days old
pregnant women at a higher risk of being carriers are offered testing
what are complications of sickle cell disease
anaemia
increased risk of infection
chronic kidney disease
sickle cell crisis
stroke
avascular necrosis in large joints
pulmonary hypertension
gall stones
priapism (painful and persistent penile erections)
what is sickle cell crisis
refers to a spectrum of acute exacerbations caused by sickle cell disease which range from mild to life threatening
they can occur spontaneously or triggered by dehydration, infection, stress or cold weather
what is a vaso-occlusive crisis
known as a painful crisis - caused by the sickle shaped red cells blocking capillaries causing distal ischaemia
how is sickle cell crisis managed
low threshold for admission to hospital
treating infections that may have triggered the crisis
keep warm
good hydration (IV fluids may be required)
analgesia (NSAIDS should be avoided if there is renal impairment)
how does vaso-occlusive crisis present
pain and swelling in the hands and feet
can affect the chest, back or other areas
fever
can causing priapism in men
what is splenic sequestration crisis
caused by red blood cells blocking blood flow within the spleen. It causes an acutely enlarged and painful spleen
blood pooling in the spleen can lead to severe anaemia and hypovolaemic shock
what is the management of splenic sequestration crisis
considered an emergency
management is supportive with blood transfusions, and fluid resuscitation to treat anaemia and shock
what can splenic sequestration crisis lead to
splenic infarction - leads to hyposplenism and susceptibility to infections particularly to encapsulated bacteria (strep. pneumoniae and Haem. influenzae
what can be done to prevent sequestration crises
splenectomy - used in recurrent cases
what is aplastic crisis
it is a temporary absence in the creation of new red blood cells in sickle cell
what can trigger aplastic crisis in sickle cell disease
parvovirus B19
what are affects of aplastic crisis
significant anaemia
what is the treatment of aplastic crisis
blood transfusions
supportive management
how long does it take aplastic crisis to resolve
usually resolves spontaneously within a week
what is acute chest syndrome
this is when vessels supplying the lungs become clogged with red blood cells
what can trigger an acute chest syndrome
vaso-occlusive crisis
fat embolism
infection
how does acute chest syndrome present
presents with fever
shortness of breath
chest pain
cough
hypoxia
what will a chest Xray show in acute chest syndrome
pulmonary infiltrates
how is acute chest syndrome managed
medical emergency
analgesia
good hydration - IV fluids
antibiotics or antivirals for infection
blood transfusions
incentive spirometry using a machine that encourages effective and deep breathing
respiratory support with oxygen, non invasive ventilation or mechanical ventilation
what is the general management for sickle cell disease
specialist MDT
avoid triggers or crisis such as dehydration
up to date vaccines
antibiotic prophylaxis typically with penicillin V
hydroxycarbamide - stimulates HbF
crizanlizumab
blood transfusions
bone marrow transplant
how does hydroxycarbamide work
works by stimulating the production of fetal haemoglobin which doesnt lead to sickling of red blood cells
- reduces frequency of vaso-occlusive crises improves anaemia and may extend lifespan
what is crizanlizumab
it is a monoclonal antibody that targets P-selectin
P-selectin is an adhesion molecule found on endothelial cells on the inside walls of blood vessels and platelets
it prevents red blood cells from sticking to the blood vessel wall
what is thalassaemia
it is a genetic defect in the protein chains that make up haemoglobin
- defects in the alpha globin chains leads to alpha thalasaemia
- defects in the beta globin chains leads to beta thalassaemia
what is the inheritance pattern of thalassaemia
autosomal recessive
why does thalassaemia cause splenomegaly
because in thalassaemia the red blood cells are more fragile and broken down easier, the spleen filters and removes the broken down red blood cells at a more rapid rate leading the splenomegaly
why does thalassaemia lead to prominent features such as a pronounced forehead and cheekbones
because the bone marrow expands to produce extra red blood cells to compensate for the chronic anaemia
this causes susceptibility to fractures and prominent features
what are potential signs and symptoms of thalassaemia
microcytic anaemia
fatigue
pallor
jaundice
gallstones
splenomegaly
poor growth and development
pronounced forehead and malar eminences
how is thalassaemia diagnosed
full blood count shows microcytic anaemia
haemoglobin electrophoresis is used to diagnose globin abnormalities
DNA testing
pregnant women in the UK are offered a screening test for thalassaemia at booking
why does iron overload happen in thalassaemia
it happens as a result of the faulty creation of ref blood cells, recurrent transfusions and increased absorption of irion in the gut in response to anaemia
how is iron overload managed in thalassaemia
patients have serum ferritin levels monitored to check for iron overload
limiting of transfusions
performing iron chelation
what are the symptoms of iron overload in thalassaemia
fatigue
liver cirrhosis
infertility
impotence
heart failure
arthritis
diabetes
osteoporosis and joint pain
what is the chromosomal abnormality in alpha thalassaemia
mutation on chromosome 16
what is the management of alpha thalassaemia
monitoring of full blood count
monitoring of complications
blood transfusions
splenectomy may be performed
bone marrow transplant may be curative
what is the genetic defect in beta thalassaemia
caused by mutation on chromosome 11
what are the different types of beta thalassemia
thalassaemia minor
thalassaemia intermedia
thalassaemia major
what is thalassaemia minor
this is when patients are carriers of an abnomally functioning beta globin gene
- one normal one abnormal
- causes a mind microcytic anaemia
what is thalassaemia intermedia
patients have two abnormal copies of the beta globin gene which can be either two defective or one defective and one deletion
- causes more significant microcytic anaemia
- require monitoring and some transfusions
- may require iron chelation
what is thaassaemia major
homozygous for the deletion genes meaning they have no functioning beta globin genes at all
the most severe form usually presents with severe aneamia and failure to thrive in early childhood
what are complications of thalassemia major
severe microcytic anaemia
splenomegaly
bone deformities
what is the management of thalassaemia major
regular transfusions
iron chelation
splenectomy
bine marrow transplant
what is hereditary spherocytosis
a condition where the red blood cells are sphere shaped making them fragile and easily destroyed when passing through the spleen
what is the inheritance pattern of hereditary spherocytosis
autosomal dominant
how does hereditary spherocytosis present
jaundice
anaemia
gallstones
splenomegaly
episodes of haemolytic crisis
aplastic crisis
what can cause haemlytic crisis in hereditary spherocytosis
infections
what can cause aplastic crisis in hereditary spherocytosis
infection with parvovirus
- presents with anaemia, haemolysis and jaundice
how is hereditary spherocytosis diagnosed
family history
clinical features
spherocytes on blood film
MCHC will be raised
reticulocytes will be raised
what is the management if hereditary spherocytosis
folate supplementation
splenectomy
removal of the gallbladder may be required
transfusions during acute crisis
what is G6PD deficiency
it is a defect in the G6PD enzyme in cells which is responsible for protecting cells from ROS damage
what is the inheritance pattern of G6PD deficiency
X linked recessive
what are triggers of G6PD crisis
infections
medications
fava beans
what is the pathophysiology of G6PD deficiency
G6PD prevents cell damage due to ROS, which are reactive molecules produced during normal cell metabolism and in higher quantities during cell stress
G6PD enzyme is particularly important in red blood cells and a deficiency in G6PD makes cells more vulnerable to ROS leading to haemolysis of red blood cells
what is the presentation of G6PD
neonatal jaundice
anaemia
intermittent jaundice - in response to triggers
gall stones
splenomegaly
what can be seen on a blood film in G6PD deficiency
Heinz bodies - denatured haemoglobin seen within red blood cells
how is G6PD deficiency diagnosed
by doing a G6PD enzyme assay
what is the management of G6PD deficiency
people should avoid triggers where possible
what medications should be avoided in G6PD deficiency
primaquine
ciprofloxacin
nitrofurantoin
trimethoprim
sulfonylureas
sulfasalazine and other sulphonamide drugs
what is haemolytic disease of the newborn
due to incompatibility between mother and babies resus group or ABO group causing the babies red blood cells to break up more quickly that usual
how does haemolytic disease of the newborn occur
when a small amount of babies blood is exposed to the mothers blood circulation during pregnancy, the mother produces antibodies to the babies blood. these antibodies are able to cross the placenta and enter the babies circulation causing red cell haemolysis
how is haemolytic disease of the newborn diagnosed
direct antibody test - DAT
either on the cord blood or directly on babies blood
what are signs of haemolytic disease of the newborn in babies
high bilirubin levels causing jaundice
anaemia
respiratory distress
lethargy
increased effort of breathing
breathlessness
how is haemolytic disease of the newborn treated
jaundice - phototherapy
blood transfusions
folic acid
monitoring of baby - follow up clinic checking babies haemoglobin levels
what is fanconi anaemia
inherited disease caused by mutations in the FA genes (23 different genes) causing bone marrow failure, where the bone marrow doesnt create healthy blood cells and platelets
how many children born with fanconi anaemia have physical abnormalities
about 75%