Anemias in Children

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Definition & Classification - Anemia ABCs

  • Definition: Hemoglobin (Hb) or Hematocrit (Hct) concentration >2 Standard Deviations (SD) below the mean for age and sex.
  • WHO Hb Cutoffs (g/dL):
    • 6 months - 5 years: <11
    • 5 - 11 years: <11.5
    • 12 - 14 years: <12

⭐ The most common type of anemia globally and in children is Iron Deficiency Anemia.

Iron Deficiency Anemia - Rusty Pipes Puzzles

  • Etiology: Inadequate intake (exclusive breastfeeding >6 months, cow's milk), prematurity, chronic blood loss (hookworm), malabsorption.
  • Clinical Features: Pallor, fatigue, irritability, pica. Koilonychia (spoon nails), glossitis.
    • Peripheral smear: microcytic hypochromic RBCs
  • Investigations:
    • CBC: ↓Hb, ↓MCV (<80 fL), ↓MCH, ↓MCHC, ↑RDW (>15%).
    • Iron Profile: ↓S. Ferritin (<15 ng/mL or <30 ng/mL with inflammation), ↓S. Iron, ↑TIBC, ↓Transferrin saturation (<16%). 📌 TIBC ↑, Ferritin ↓.
  • Management:
    • Oral elemental iron: 3-6 mg/kg/day.
    • Continue for 2-3 months after Hb normalizes.

⭐ Exclusive breastfeeding beyond 6 months without iron supplementation is a major risk factor for IDA in infants.

Megaloblastic Anemias - Big Cell Conundrums

Impaired DNA synthesis. MCV > 100 fL. Smear: macro-ovalocytes, hypersegmented neutrophils (>5% with 5 lobes or any with 6 lobes).

FeatureVit B12 DeficiencyFolate Deficiency
CausesPernicious anemia, gastrectomy, vegan, D. latumGoat's milk, poor diet, MTX, phenytoin, ↑demand
Neuro SxYES (SCD)NO
Labs↓B12, ↑MMA, ↑Homocysteine↓Folate, N MMA, ↑Homocysteine

⭐ Goat's milk (folate-deficient) → megaloblastic anemia in infants if primary feed, unsupplemented.

Hemolytic Anemias - Red Cell Rampage

  • Increased RBC destruction. Key signs: ↑Reticulocytes, ↑Indirect Bilirubin, ↓Haptoglobin, Splenomegaly.
  • Diagnostic Approach:
  • Common Hereditary Hemolytic Anemias:

    FeatureThalassemia Major (β-thal)Sickle Cell Anemia (SCA)Hereditary Spherocytosis (HS)
    Defect↓/absent β-globin chainsAbnormal β-globin (HbS)RBC membrane protein defect (e.g., spectrin)
    SmearTarget cells, microcytic, hypochromic, NRBCsSickled cells, Howell-Jolly bodiesSpherocytes, ↑MCHC
    Hb Electrophoresis↑HbF, ↑HbA2 (>3.5% for trait), ↓/absent HbAHbS predominant, HbF variable, no HbANormal (usually)
    Specific TestHb electrophoresisSickling test, Hb electrophoresisOsmotic fragility test, EMA binding
  • 📌 SCA Crisis Triggers (FAT RBC): Fever, Acidosis, Temperature changes, Reduced O2, Dehydration, Exertion, Stress.

  • Peripheral smear: Sickled cells, spherocytes, target cells

⭐ Hydroxyurea increases HbF levels and is used in the management of Sickle Cell Anemia to reduce crisis frequency.

Aplastic & Other Anemias - Marrow Meltdown

  • Aplastic Anemia (AA): Pancytopenia, hypocellular marrow. Causes: idiopathic, drugs, viruses.

    • Severe: BM <25% + 2 of: ANC <0.5, Plt <20, Retic <20 (x10⁹/L).
    • Tx: IST, HSCT. Normal vs Hypocellular Bone Marrow
  • Fanconi Anemia (FA): AR, DNA repair defect → pancytopenia. Café-au-lait, thumb/radial defects. Dx: DEB test.

  • Diamond-Blackfan Anemia (DBA): Congenital PRCA. Macrocytic anemia, reticulocytopenia. Craniofacial/thumb defects. ↑eADA.

    ⭐ Diamond-Blackfan Anemia is a congenital pure red cell aplasia often associated with craniofacial and thumb abnormalities, and elevated erythrocyte adenosine deaminase (eADA).

  • Transient Erythroblastopenia of Childhood (TEC): Acquired PRCA (1-4y), post-viral. Spontaneous recovery.

High‑Yield Points - ⚡ Biggest Takeaways

  • Iron Deficiency Anemia (IDA): Most common; screen at 9-12 months; microcytic, hypochromic.
  • Thalassemia Major: Severe anemia at 6-9 months, hepatosplenomegaly, requires lifelong transfusions.
  • Sickle Cell Anemia: Crisis by hypoxia, infection, dehydration; hydroxyurea ↑ HbF.
  • G6PD Deficiency: Hemolysis with oxidant drugs (e.g., primaquine) or fava beans.
  • Hereditary Spherocytosis: Microspherocytes, ↑ MCHC, osmotic fragility; splenectomy is curative.
  • Aplastic Anemia: Pancytopenia with hypocellular bone marrow.

Practice Questions: Anemias in Children

Test your understanding with these related questions

A 29-year-old woman was found to have a hemoglobin level of 7.8 mg/dl, with a reticulocyte count of 0.8%. The peripheral blood smear showed microcytic hypochromic anemia. On high-performance liquid chromatography (HPLC), hemoglobin A2 and hemoglobin F were 2.4% and 1.3%, respectively. The serum iron and total iron-binding capacity (TIBC) were 15 mg/dl and 420 micrograms per deciliter, respectively. What is the most likely cause of anemia in this patient?

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Flashcards: Anemias in Children

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Hb _____ levels are increased in juvenile chronic myeloid leukemia (JMML)

TAP TO REVEAL ANSWER

Hb _____ levels are increased in juvenile chronic myeloid leukemia (JMML)

F

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