Page 9 of 23

PA14.1-2 | Welcome to Microcytic Anaemia Differentials: Thalassaemia, ACD, Sideroblastic

Learning Objectives

  • Build a systematic approach to distinguish the four major causes of microcytic anaemia using the TAILS mnemonic
  • Identify the key laboratory discriminators between IDA, thalassaemia trait, anaemia of chronic disease, and sideroblastic anaemia
  • Apply the Mentzer Index and iron study profile to generate a working diagnosis before requesting advanced tests
  • Recognise the Indian-population context for beta-thalassaemia trait screening and the role of HPLC
  • Name the pathognomonic smear findings for each differential: target cells, dimorphic population, ringed sideroblasts, basophilic stippling

INSTRUCTIONS

You have learned iron metabolism (SDL1) and the full IDA story (SDL2). Now comes the diagnostic challenge: not every microcytic anaemia is iron deficiency. Treating the wrong diagnosis causes patient harm — iron therapy in thalassaemia trait accelerates iron overload; missing ACD delays treatment of the underlying disease. This SDL builds your diagnostic decision tree so you never treat microcytosis blindly.

References

  • Robbins and Cotran Pathologic Basis of Disease, 10th ed. — Chapter 14: Red Cell Disorders (textbook)
  • Wintrobe's Clinical Hematology, 14th ed. — Chapter 23: Differential Diagnosis of Anaemia (textbook)
  • Dacie and Lewis Practical Haematology, 12th ed. — Chapters 5 and 16 (textbook)
  • Indian Council of Medical Research (ICMR): Guidelines for Thalassaemia Carrier Screening, 2023 (guideline)
  • Harrison's Principles of Internal Medicine, 21st ed. — Chapter 100: Iron Deficiency and Other Hypochromic Anaemias (textbook)

Version 2.0 | NMC CBUC 2024