Anemias in Children

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.
  • 
• 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).

⭐ 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:

  Feature	Thalassemia Major (β-thal)	Sickle Cell Anemia (SCA)	Hereditary Spherocytosis (HS)
  Defect	↓/absent β-globin chains	Abnormal β-globin (HbS)	RBC membrane protein defect (e.g., spectrin)
  Smear	Target cells, microcytic, hypochromic, NRBCs	Sickled cells, Howell-Jolly bodies	Spherocytes, ↑MCHC
  Hb Electrophoresis	↑HbF, ↑HbA2 (>3.5% for trait), ↓/absent HbA	HbS predominant, HbF variable, no HbA	Normal (usually)
  Specific Test	Hb electrophoresis	Sickling test, Hb electrophoresis	Osmotic fragility test, EMA binding

• 📌 SCA Crisis Triggers (FAT RBC): Fever, Acidosis, Temperature changes, Reduced O2, Dehydration, Exertion, Stress.

• 

⭐ 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.

• 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.