Paeds · haematology-oncology-and-transfusion
Anaemia: diagnostic approach
Also known as Pediatric anemia workup · MCV-based anaemia classification · Anaemia evaluation in children · Low haemoglobin diagnostic approach · Red cell indices interpretation
Fellowship MCV-based diagnostic approach to confirmed paediatric anaemia: age-specific haemoglobin thresholds, the microcytic or normocytic or macrocytic grid combined with reticulocyte kinetics and the peripheral film, directed second-line testing, and how to avoid the common traps of over-treating iron and missing marrow failure.
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Red flags
- Multi-lineage cytopenias with neutropenia or thrombocytopenia alongside anaemia
- Fever with bruising, petechiae, bone pain or hepatosplenomegaly suggesting malignancy
- Acute haemolysis with falling haemoglobin, jaundice and dark urine
- Severe anaemia with cardiac failure, shock or altered consciousness
- Pancytopenia or hypoplastic marrow picture suggesting aplastic anaemia
- Microcytosis that does not correct with an adequate iron course
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- General and Community Paediatrics
- Paediatric haematology — laboratory approach to anaemia
- Renewed curriculum for first-year trainees from 2027 — Learning goal 5: Clinical assessment and essential general paediatrics
- Renewed curriculum for first-year trainees from 2027 — Learning goal 11: Investigation and management of common conditions
- Clinical Applications — interpretation of the full blood count
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- Short Cases
- 4. Professional skills and knowledge: Patient management
- General Paediatrics: Interprets the abnormal full blood count and directs anaemia investigations
- Foundation of Practice (FOP) — haematology
- Applied Knowledge in Practice (AKP) — anaemia workup
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- General Pediatrics Content Outline — Hematology
- General Pediatrics Content Outline — Interpretation of diagnostic studies
- Patient Care 4: Clinical Reasoning
- Medical Knowledge 1: Clinical Knowledge — haematology
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- Scholar — investigation of paediatric anaemia
A low haemoglobin is a pattern, not a verdict. The child in front of you drank a litre of cow's milk a day, or just finished a viral illness, or carries thalassaemia trait silently, or has a marrow that has stopped making cells. Each story produces the same abnormal number but demands a different next step. This leaf owns the laboratory reasoning that converts that number into a mechanism, then into a directed investigation. [1] [2]
The bedside sign of pallor and the threat-first stabilisation of the sick child sit in a companion leaf; this page begins once the full blood count is in your hand. Cross-link the pallor page for recognition across skin tones and the disease-specific leaves for iron deficiency, haemolysis and macrocytic anaemia protocols. [1]
Mean corpuscular volume sorts micro, normo or macro · Confirm with a reticulocyte count · View the peripheral film · Reticulocytes high means loss or haemolysis · Exclude marrow failure when reticulocytes stay low · Treat the cause, then iron only when iron-deficient · Iron response proves the diagnosis · Check platelets and white cells for multi-lineage disease. [1] [6]
Overview & Definition
Anaemia is a laboratory definition. The World Health Organization sets age- and sex-specific haemoglobin cut-offs below which anaemia exists. For children aged six months to under five years the threshold is a haemoglobin below 110 g per litre; for children five to eleven years it is below 115 g per litre; for children twelve to fourteen years and for non-pregnant females aged fifteen years and older it is below 120 g per litre. Pregnancy and altitude lower and raise these bands respectively. [2]
A haemoglobin value alone tells you nothing about cause. The job of the diagnostic approach is to move from "the number is low" to "here is the mechanism", using red-cell size, marrow response and morphology. The same haemoglobin of 70 g per litre can mean dietary iron deficiency in a toddler, acute autoimmune haemolysis in a school-age child, or aplastic anaemia in an adolescent, and the next investigation differs for each. [1] [6]
Severity is graded against the same age bands. For a child under five years, haemoglobin of 100 to 109 g per litre is mild, 70 to 99 g per litre is moderate, and below 70 g per litre is severe. Severe anaemia is a medical urgency regardless of cause, because oxygen delivery and cardiac reserve are compromised. [2]
References12ShowHide
- [1]Wang M Iron Deficiency and Other Types of Anemia in Infants and Children. American family physician, 2016.PMID 26926814
- [2]Allali S Anemia in children: prevalence, causes, diagnostic work-up, and long-term consequences. Expert review of hematology, 2017.PMID 29023171
- [3]Pasricha SR Iron deficiency. Lancet (London, England), 2021.PMID 33285139
- [4]Leung AKC Iron Deficiency Anemia: An Updated Review. Current pediatric reviews, 2024.PMID 37497686
- [5]Short MW Iron deficiency anemia: evaluation and management. American family physician, 2013.PMID 23317073
- [6]Celkan TT What does a hemogram say to us? Turkish archives of pediatrics, 2020.PMID 32684755
- [7]Baird DC Alpha- and Beta-thalassemia: Rapid Evidence Review. American family physician, 2022.PMID 35289581
- [8]Muncie HL Jr Alpha and beta thalassemia. American family physician, 2009.PMID 19678601
- [9]Stabler SP Clinical practice. Vitamin B12 deficiency. New England Journal of Medicine, 2013.PMID 23301732
- [10]Socha DS Severe megaloblastic anemia: Vitamin deficiency and other causes. Cleveland Clinic journal of medicine, 2020.PMID 32127439
- [11]Weiss G Anemia of chronic disease. New England Journal of Medicine, 2005.PMID 15758012
- [12]Lanphear B Lead Poisoning. New England Journal of Medicine, 2024.PMID 39476342