Iron Deficiency — Written Clinical Reasoning

Model answer — Part A: severe iron-deficiency anaemia in an older man

Frame the problem. This is confirmed absolute iron-deficiency anaemia — ferritin 12 µg/L with TSAT 7% admits no argument — with a reactive thrombocytosis typical of chronic blood loss. In a 68-year-old man, the working diagnosis is occult GI blood loss, and GI malignancy must be excluded; the ibuprofen is a contributor to prove innocent, not a cause to assume ^{[1] [3]}.

Assessment. Establish severity and stability: symptoms of anaemia (exertional dyspnoea, angina, syncope), haemodynamic observations, and any red flags — weight loss, anorexia, change in bowel habit, dysphagia, family history of GI cancer. Medication review for NSAIDs, anticoagulants and antiplatelets; dietary history; examination for abdominal masses, lymphadenopathy and PR findings ^[1].

Investigations. Complete the phenotype first: B12/folate, renal and liver function, CRP, reticulocytes and film. Then the cause hunt: coeliac serology (tTG-IgA with total IgA) and bidirectional endoscopy — gastroscopy with duodenal biopsies plus colonoscopy — because in this demographic a causative GI lesion is found in the majority and roughly one in ten harbours a cancer; a negative FOBT would change nothing and should not be performed as a gatekeeper ^{[1] [2] [4]}.

Management. Transfusion is NOT indicated in a stable, compensating patient — iron deficiency is treated with iron. Start oral ferrous sulfate (65 mg elemental iron per tablet) once daily or alternate days on an empty stomach if tolerated, counsel on side effects, and stop the ibuprofen. Set expectations: reticulocyte response within about a week, haemoglobin rise of about 20 g/L per 2–3 weeks, and continue about 3 months after normalisation to replete stores. Switch to IV iron if oral iron fails or is not tolerated. Close the loop: recheck Hb and ferritin at 4 weeks, and ensure the endoscopy happens regardless of how the numbers respond ^{[3] [8]}.