Microcytic anaemia

Once daily FeSO4, or one every other day, is enough. Please stop prescribing 3x/day oral iron as this only causes more side effects

About

• Reduced Hb for age/sex
• Small red cells < 80 fl

Aetiology

• Red cell production is driven by Erythropoietin.
• If cells cannot receive adequate haemoglobin they undergo more divisions
• This means they end up small - microcytic
• The limiting factors in each is shown in brackets

Causes

Clinical

• Fatigue, tiredness, Anaemia, Koilonychia - spoon-shaped nails
• Brittle nails and hair, Glossitis
• Flow murmurs, Menstrual losses, Use of NSAID, Aspirin
• GI blood loss, Poor dietary iron intake, Racial origin - ? thalassaemia

Investigation

• Microcytosis, hypochromic, anisocytosis (variability in size), poikilocytosis (variation in shape)
• Low serum iron and Low Ferritin
• Raised Total iron-binding capacity (TIBC)
• Transferrin saturation is low (serum iron/TIBC)
• Raised Serum soluble transferrin receptors
• Bone marrow - erythroid hyperplasia and low Iron content
• OGD and Colonoscopy
• Small bowel investigations
• Technetium labelled red cell scans
• Uterine/Pelvic USS and investigation of PV losses
• HB electrophoresis

Causes of Iron deficiency anaemia

• Blood loss - GI tract, Urinary blood loss, Epistaxis, Hookworm, Menstrual
• Trauma/surgical losses
• Pregnancy and growth with increased demand
• Malabsorption - Coeliac
• Poor intake

Management

• Identify and investigate cause - most commonly OGD + Colonoscopy for Iron deficiency
• Ferrous sulphate 200 mg OD or alternate days for 6 months
• Response shows a rise in reticulocytes and Hb by 1 g/week
• Treat lead toxicity and pyridoxine may help some sideroblastic anaemia
• Transfusion is the main treatment if cause untreatable