Makindo Medical Notes

Related Subjects: |Iron deficiency Anaemia |Haemolytic anaemia |Macrocytic anaemia |Megaloblastic anaemia |Microcytic anaemia |Myelodysplasia |Myelofibrosis

⚠️ Iron deficiency anaemia in an older patient = gastrointestinal malignancy until proven otherwise. 👉 Always investigate with both upper GI endoscopy and colonoscopy.

📖 About

• Always consider gastrointestinal malignancy until excluded 🚨

🧬 Aetiology

• Poor intake, excess loss, or increased utilisation (most iron is normally reused).
• There is a latent period of iron loss before anaemia becomes clinically evident.

🩸 Causes

• Gastrointestinal blood loss (most common in adults)
• Menstrual blood loss
• Pregnancy (↑ requirements)
• Dietary deficiency
• Hookworm 🪱 (commonest worldwide)
• Schistosomiasis
• Paterson–Brown–Kelly (Plummer–Vinson) syndrome

🩺 Clinical Features

• Fatigue, pallor, exertional breathlessness
• Koilonychia – spoon-shaped nails
• Pallor of conjunctiva & palmar creases
• Brittle nails, hair loss, cheilosis, glossitis
• Flow murmurs (high-output state)
• Pica – craving ice (pagophagia) or clay (geophagia)

🔎 Investigations

• Microcytic, hypochromic anaemia (low MCV, hypochromic RBCs, low reticulocytes)
• Low serum ferritin (best marker unless infection/inflammation present)
• Plasma iron ↓, TIBC ↑
• Soluble transferrin receptor ↑ (helps distinguish from anaemia of chronic disease)
• Transferrin saturation < 15% → impaired Hb synthesis

📊 Key Components of Iron Studies

• Serum Iron: 10–30 µmol/L (55–160 µg/dL)
• TIBC: 45–70 µmol/L (250–450 µg/dL)
• Transferrin Saturation: 20–50%
• Ferritin: 15–300 µg/L (men), 15–200 µg/L (women)

🧾 Interpreting Iron Studies

The pattern of iron studies helps distinguish IDA from anaemia of chronic disease and iron overload states:

🧪 Additional Investigations

• Rectal exam, proctoscopy → exclude rectal tumour, piles
• Upper GI endoscopy ± jejunal biopsy → ulcers, coeliac disease
• Colonoscopy → polyps, malignancy, colitis
• Serology → Anti-endomysial, Anti-tTG (coeliac)
• Stool/urine → parasites
• Gynae/urology → menorrhagia or haematuria causes
• Small bowel MRI or capsule endoscopy → obscure bleeding
• Meckel’s scan → ectopic gastric mucosa
• Angiography → severe occult bleeding

💊 Oral iron: Once daily FeSO₄ (or alternate day) is usually sufficient. ❌ Stop 3x/day dosing – only ↑ side effects (constipation, nausea).

💊 Management

• Identify & treat the cause (GI malignancy until excluded).
• FeSO₄ 200 mg once daily or alternate days × 6 months. Expect Hb ↑ ~1 g/dL/week with response.
• Parenteral iron if intolerance to oral iron or need for rapid correction (e.g. pre-op).
• Blood transfusion if severe anaemia with symptoms or haemodynamic compromise.

Cases — Iron Deficiency Anaemia (IDA)

• Case 1 — Menorrhagia in a Young Woman: A 28-year-old woman presents with fatigue, pallor, and hair thinning. She reports heavy menstrual periods lasting 7 days. FBC: Hb 9.4 g/dL, MCV 71 fL, ferritin 7 µg/L. Diagnosis: IDA secondary to menorrhagia.
• Case 2 — Elderly Man with Occult GI Bleeding: A 74-year-old man complains of lethargy and exertional dyspnoea. No overt bleeding. Hb 8.2 g/dL, MCV 65 fL, ferritin 9 µg/L. FIT test positive, colonoscopy reveals a right-sided colonic adenocarcinoma. Diagnosis: IDA from chronic gastrointestinal blood loss (malignancy).
• Case 3 — Child with Poor Diet: A 5-year-old boy has irritability, pica (soil craving), and poor growth. Diet is low in meat and vegetables, dominated by cow’s milk. Hb 7.6 g/dL, MCV 62 fL, ferritin 5 µg/L. Diagnosis: Nutritional IDA in childhood.
• Case 4 — Post-Gastrectomy Malabsorption: A 60-year-old woman who had partial gastrectomy 10 years ago presents with fatigue and brittle nails. Hb 8.9 g/dL, MCV 68 fL, ferritin 11 µg/L. Normal B12 and folate. Diagnosis: IDA secondary to impaired absorption (post-gastrectomy).
• Case 5 — Pregnancy-Associated IDA: A 30-year-old woman at 28 weeks gestation reports tiredness and shortness of breath. Hb 9.0 g/dL, MCV 69 fL, ferritin 10 µg/L. She has not been taking iron supplementation. Diagnosis: IDA due to increased requirements in pregnancy.

Teaching Commentary 🩸

IDA is the most common anaemia worldwide. Core labs: low Hb, microcytosis, low ferritin. Causes are diverse: - Blood loss (menorrhagia, GI cancer, peptic ulcer, hookworm), - Poor intake (children, elderly, restrictive diets), - Malabsorption (gastrectomy, coeliac disease), - Increased demand (pregnancy, growth). Clinical features include fatigue, pallor, glossitis, angular cheilitis, koilonychia, and pica. Always treat the cause and replenish iron stores (oral ferrous sulfate/fumarate/gluconate, or IV iron if malabsorptive or intolerant). In UK practice, unexplained IDA in men or postmenopausal women mandates urgent GI investigation for malignancy.