Anaemia Flashcards
Causes of microcytic anaemia
Iron deficiency Chronic disease, malignancy Lead poisoning Congenital sideroblastic anaemia Thalassaemia in South Asians Polycythaemia rubra vera in non-South Asians
Types of thalassaemia
Beta trait, beta major and alpha
Beta trait thalassaemia
Common, causes mild hypochromic microcytic anaemia. Often asymptomatic. Hba2 raised.
Beta major thalassaemia
No beta chains. Presents in first year as failure to thrive and hepatosplenomegaly. Hba and HbF raised. Hba absent.
Treat with repeated transfusion and s/c deferoxamine.
Alpha thalassaemia
Deficiency in alpha chains. 2 separate chains on each chromosome 16. Have from 1-4 effected.
1/2 effected- hypochromic microcytic anaemia but Hb normal.
3 effected- hypochromic microcytic anaemia and splenomegaly.
4 effected- in-utero death.
Causes of macrocytic anaemia
Megaloblastic (reticulocytes big):
B12 deficiency, folate deficiency
Normoblastic:
Alcohol, liver disease, pregnancy, myelodysplasia, hypothyroid, cytotoxic drugs
What is pernicious anaemia?
Cause of macrocytic anaemia due to B12 deficiency due to antibodies to intrinsic factor.
Ab attack intrinsic factor and gastric parietal cells.
Symptoms: enlarged sore tongue, jaundice, poor concentration, confusion, depression, weakness, paraesthesia, pins and needles.
FBC: macrocytic anaemia, hypersegmented polymorphs
Other causes of B12 deficiency
Erosive gastritis, H pylori, gastrectomy, malnourishment, alcoholism
Management of pernicious anaemia
If no neurological features- 3 injections of B12 per week for 2 weeks, then every 3 months.
More often is neurological symptoms.
What is sickle cell disease?
Autosomal recessive condition, abnormal haemoglobin chain, more common in Africans.
Causes sickle shaped RBCs which haemolyse and block small vessels.
Diagnose with Hb electrophoresis.
Types of sickle cell crisis
Thrombotic crisis Sequestration crisis Acute chest syndrome Aplastic crisis Haemolytic crisis
Sickle cell thrombotic crisis
Lots of tiny blockages. AKA painful crisis.
Infarcts in various organs can cause necrosis of hip, hand, foot, lungs and spleen.
Sickle cell sequestration crisis
Pooling of blood within organs e.g. spleen and lungs.
Worsening anaemia- tiredness and lethargy.
Sickle cell acute chest syndrome
Chest pain and pulmonary infiltrates. Hypoxia. Most common cause of sickle cell death.
Aplastic crisis
Caused by infection with parvovirus
See sudden fall in Hb.
