Microcytic Anaemia

Question 1

Definition

Answer 1

Anaemia associated with a low MCV (< 80 fl)

Question 2

Aetiology

Answer 2

• Iron Deficiency - MOST COMMON
o Iron deficiency can be caused by:
• Blood loss (e.g. GI)
• Reduced absorption (e.g. small bowel disease)
• Increased demands (e.g. growth, pregnancy)
• Reduced intake (e.g. vegans)
Overall problem with absorption or blood loss somewhere

• Anaemia of Chronic Disease
o Microcytic anaemia in a patient with chronic disease

• Thalassemia

• Sideroblastic Anaemia
o Abnormality of haem synthesis
o It can be inherited or it can be secondary (e.g. to alcohol, drugs)

Question 3

Epidemiology

Answer 3

Iron deficiency anaemia is the MOST COMMON form of anaemia worldwide

Can either be:
Iron deficiency anaemia (high transferrin)
Beta thalassaemia
Anaemia of chronic disease (high ferritin and low/normal transferrin)

Question 4

Presenting symptoms (non-specific)

Answer 4

o Tiredness
o Lethargy
o Malaise
o Dyspnoea
o Pallor
o Exacerbation of ischaemic conditions (e.g. angina, intermittent claudication)

Question 5

Presenting symptoms (lead poisoning)

Answer 5

Lead Poisoning - can cause microcytic anaemia

Symptoms of lead poisoning
o Anorexia
o Nausea/Vomiting
o Abdominal pain
o Constipation
o Peripheral nerve lesions

Question 6

Signs on physical examination

Answer 6

• Signs of anaemia
o Pallor
o Brittle nails and hair
o Koilonychia (if severe)

• Glossitis
• Angular stomatitis
• Signs of thalassemia

Question 7

Signs on physical examination (lead poisoning)

Answer 7

Lead poisoning signs:
o Blue gumline
o Peripheral nerve lesions (causing wrist or foot drop)
o Encephalopathy
o Convulsions
o Reduced consciousness

Question 8

Investigations (bloods)

Answer 8

o FBC
• Low Hb
• Low MCV
• Reticulocytes

o Serum iron (low in iron deficiency)
o Total iron binding capacity (high in iron deficiency)
o Serum ferritin (low in iron deficiency)
o Serum lead

Transferrin is high in iron deficiency anaemia

Question 9

Investigations (blood film)

Answer 9

o Iron deficiency anaemia:
• Microcytic
• Hypochromic
• Anisocytosis
• Poikilocytosis

o Sideroblastic anaemia:
• Dimorphic blood film
• Hypochromic microcytic cells

o Lead poisoning:
• Basophilic stippling

Question 10

Investigations (other)

Answer 10

• Hb Electrophoresis
o Checking for haemoglobin variants and thalassemia

• Sideroblastic Anaemia
o Ring sideroblasts in the bone marrow

• Special investigations for iron deficiency anaemia if > 40 yrs and post-menopausal women

These are considered if no obvious cause of blood loss is identified
o Upper GI endoscopy
o Colonoscopy
o Haematuria

Younger people would order upper GI endoscopy first as peptic ulcer common cause

Older people would order colonoscopy as colonic cancer a common cause of bleeding/iron deficiency anaemia

Question 11

Management plan (iron deficiency anaemia)

Answer 11

Oral iron supplements

Question 12

Management plan (sideroblastic anaemia)

Answer 12

o Treat the cause
o Pyridoxine used in inherited forms
o Blood transfusion and iron chelation can be considered if there is no response to other treatments

Question 13

Management plan (lead poisoning)

Answer 13

o Remove the source
o Dimercaprol
o D-penicillinamine

Question 14

Possible complications

Answer 14

• High-output cardiac failure

* Complications related to the CAUSE

Question 15

Prognosis

Answer 15

Depends on the CAUSE