Microcytic anaemia

Question 1

Define

Answer 1

MCV <80 fl

Question 2

Causes

Answer 2

1. Iron deficiency anaemia (most common) due to blood loss e.g. GI tract

↓absorption (small bowel disease, post gastrectomy), ↑demands (growth, pregnancy)↓intake (vegans)

2. Thalassemia
3. Sideroblastic anaemia (v rare): abnormality of haem synthesis, can be inherited (X-linked) or due to alcohol/drugs/lead poisoning

Question 3

Epidemiology

Answer 3

iron deficiency anaemia is commonest cause worldwide

Question 4

Symptoms

Answer 4

non-specific symptoms of anaemia
Lead poisoning: anorexia, N&V, abdomen pain, constipation, peripheral nerve lesions

Question 5

Signs

Answer 5

Signs of anaemia (e.g. pallor)

• Brittle nails and hair
• Koilonychia if long-standing
• Glossitis (atrophy of tongue papillae)  Chelitis (angular stomatitis)

Lead poisoning: blue gum line, peripheral nerve lesions (wrist/foot drop), encephalopathy, convulsions, ↓consciousness

Question 6

Investigations

Answer 6

Blood – FBC (↓Hb, ↓MCV, reticulocytes),
In Fe deficiency: ↓iron, ↑iron binding capacity, ↓serum ferritin Serum lead in lead poisoning

Blood film: microcytic, hypochromic (central pallor >1/3 size), Anisocytosis (variable size), poikilocytosis (variable shapes)

Sideroblastic anaemia: Dimorphic blood film with a population of hypochromic microcytic cells
Lead poisoning: Basophilic stippling (coarse dots represent condensed RNA in cytoplasm)

Note: if iron-deficiency anaemia in >40 years and post- menopausal women – upper GI endoscopy, colonoscopy and investigations for haematuria should be considered if no obvious cause of blood loss

Question 7

Management

Answer 7

• Iron deficiency: oral Few supplement (ferrous sulphate)
• Sideroblastic anaemia: treat cause (e.g. drugs), pyridoxine may be used, consider transfusion/iron chelation
• Lead poisoning: remove source, Dimercaprol, D-penicillamina, Ca2 and EDTA

Question 8

Complications

Answer 8

high output cardiac failure

Question 9

Prognosis

Answer 9

depends on underlying cause