Anaemia in children Flashcards
what is anemia?
Anemia is defined as a low level of hemoglobin in the blood. This is the result of an underlying disease and is not a disease itself. The prefix an- means without and the suffix -aemia refers to blood.
Hemoglobin?
Haemoglobin is a protein found in red blood cells. It is responsible for picking up oxygen in the lungs and transporting it to the cells of the body. Iron is an essential ingredient in creating haemoglobin and forms part of the structure of the molecule. When a patient has a low level of haemoglobin, they have a condition called anaemia.
Causes of Anaemia In Infancy?
- Physiologic anaemia of infancy causes most cases of anaemia in infancy.
- The other causes of anaemia in infants are:
- Anaemia of prematurity
- Blood loss
- Haemolysis
- Twin-twin transfusion, where blood is unequally distributed between twins that share a placenta
- Haemolysis is a common cause of anaemia in infancy. There are a number of causes of haemolysis in a neonate:
- Haemolytic disease of the newborn (ABO or rhesus incompatibility)
- Hereditary spherocytosis
- G6PD deficiency
Causes of Physiologic Anaemia of Infancy?
- As a result of extra-uterine life i.e from a low oxygen tension environment to a high oxygen tension environment. i.e in the uterus PaO2= 45% and Outside=90%
- A newborn has low levels of erythropoietin
(Production of erythropoietin in the kidneys is suppressed and subsequently, there is reduced production of hemoglobin Hb by the bone marrow.) - Increased plasma volume leading to Haemodilution
- Survival time for RBCs is very short.
Causes of Anaemia of Prematurity?
Premature neonates become anemic for a number of reasons:
- Less time in utero receiving iron from the mother
(Iron deficiency- interruption of transfer of iron in 3rd trimester from mother to fetus). - Red blood cell creation cannot keep up with the rapid growth in the first few weeks
- Reduced erythropoietin levels
4.Blood tests remove a significant portion of their circulating volume
Causes of Haemolytic Disease of the Newborn?
- Rhesus-incompatibility- does occur when the mother is rhesus negative and the baby is rhesus positive. this provokes the mother to produce antibodies against Rhesus +ve cells, hence leading to Haemolysis(red blood cells breaking down). The baby may be born dead or alive with severe Jaundice i.e known as Haemolytic Disease of the Newborn.
- In ABO blood group system- Mother is Group O and baby is either A or B. This is a bit mild compared to the above. Jaundice occurs in the 1st 24hours of life due to incompatibility.
- Drugs like Sulphonamides
- Infections in newborn, either due to acquired or trans-infection.
- Abnormal Haemoglobin but rarely
Causes of Anaemia in Older Children >6yrs?
The key causes of anaemia in older children are:
- Iron deficiency anaemia secondary to dietary insufficiency. This is the most common cause overall.
- Blood loss, most frequently from menstruation in older girls
Rarer causes of anaemia in children include:
a) Sickle cell anaemia
b) Thalassaemia
c) Leukaemia
d) Hereditary spherocytosis
e) Hereditary eliptocytosis
f) Sideroblastic anaemia
g) Malaria
Categorisation of Anaemia?
Anaemia is initially subdivided into three main categories based on the size of the red blood cell (the MCV). These have different underlying causes:
- Microcytic anaemia (low MCV indicating small RBCs)
- Normocytic anaemia (normal MCV indicating normal-sized RBCs)
- Macrocytic anaemia (large MCV indicating large RBCs)
- Microcytic anaemia causes?
A helpful mnemonic for understanding the causes of microcytic anaemia is TAILS.
T – Thalassaemia A – Anaemia of chronic disease I – Iron deficiency anaemia L – Lead poisoning S – Sideroblastic anaemia
2.Normocytic anaemia causes?
There are 3 As and 2 Hs for normocytic anaemia:
A – Acute blood loss A – Anaemia of Chronic Disease A – Aplastic Anaemia H – Haemolytic Anaemia H – Hypothyroidism
- Macrocytic Anaemia causes?
Macrocytic anaemia can be megaloblastic or normoblastic. Megaloblastic anaemia is the result of impaired DNA synthesis preventing the cell from dividing normally. Rather than dividing it keeps growing into a large, abnormal cell. This is caused by a vitamin deficiency.
a) Megaloblastic anaemia is caused by:
* B12 deficiency
* Folate deficiency
b) Normoblastic macrocytic anaemia is caused by:
- Alcohol
- Reticulocytosis (usually from haemolytic anaemia or blood loss)
- Hypothyroidism
- Liver disease
- Drugs such as azathioprine
Symptoms of Anaemia
- There are many generic symptoms of anaemia:
- Tiredness
- Shortness of breath
- Headaches
- Dizziness
- Palpitations
- Worsening of other conditions
- There are symptoms specific to iron deficiency anaemia:
- PICA describes dietary cravings for abnormal things such as dirt and can signify iron deficiency
- HAIR LOSS can indicate iron deficiency anaemia
Signs of Anaemia
- Generic signs of anaemia:
- Pale skin
- Conjunctival pallor
- Tachycardia
- Raised respiratory rate
- Signs of specific causes of anaemia:
- Koilonychia refers to spoon shaped nails, which can indicate iron deficiency
- Angular chelitis can indicate iron deficiency
- Atrophic glossitis is a smooth tongue due to atrophy of the papillae and can indicate iron deficiency
- Brittle hair and nails can indicate iron deficiency
- Jaundice occurs in haemolytic anaemia
- Bone deformities occur in thalassaemia
Investigations of Anaemia?
Initial Investigations:
- Full blood count for haemoglobin and MCV
- Blood film
- Reticulocyte count
- Ferritin (low iron deficiency)
- B12 and folate
- Bilirubin (raised in haemolysis)
- Direct Coombs test (autoimmune haemolytic anaemia)
- Haemoglobin electrophoresis (haemoglobinopathies)
Reticulocytes are immature red blood cells. A high level of reticulocytes in the blood indicates active production of red blood cells to replace lost cells. This usually indicates the anaemia is due to haemolysis or blood loss.
Further investigation will depend on the suspected underlying cause.
