## Clinical Presentation This child has **acute hemolytic crisis triggered by G6PD deficiency** (favism). The clinical triad is: - **Hemolysis** — bite cells, Heinz bodies, elevated indirect bilirubin - **Trigger** — fava bean ingestion (oxidative stress) - **Enzyme deficiency** — G6PD activity markedly reduced ## Pathophysiology of G6PD Deficiency **Key Point:** G6PD catalyzes the first step of the **pentose phosphate pathway**, generating NADPH: $$\text{Glucose-6-phosphate} + \text{NADP}^+ \rightarrow \text{6-Phosphogluconolactone} + \text{NADPH}$$ NADPH is essential for **glutathione reduction** (GSH → GSSG), which protects RBCs from oxidative damage. Without adequate NADPH, RBCs cannot neutralize reactive oxygen species (ROS) from oxidative stressors (fava beans, sulfonamides, aspirin, infections), leading to hemolysis. ## Management of Acute Hemolytic Crisis **High-Yield:** Acute G6PD hemolysis requires **immediate intervention**: 1. **Exchange transfusion** — if severe anemia (Hb <7 g/dL) or signs of hemodynamic compromise (tachycardia, hypotension, altered mental status) 2. **Supportive care** — IV fluids, monitor urine output (prevent acute kidney injury from myoglobinuria) 3. **Avoid triggers** — strict dietary avoidance of fava beans and oxidative drugs 4. **Hematology referral** — G6PD phenotyping (Mediterranean, African, Asian variants have different severity), genetic counseling for family **Clinical Pearl:** Indirect hyperbilirubinemia >6 mg/dL in a 2-year-old with hemolysis is concerning for kernicterus risk; exchange transfusion threshold is typically <5 mg/dL in this age group, making urgent transfusion appropriate here. ## Why Option 1 (Folic Acid) Is Wrong Folic acid is indicated for **chronic hemolytic anemias** (e.g., hereditary spherocytosis, sickle cell disease) to support increased RBC production. However: - In acute G6PD crisis, the immediate threat is **severe anemia and hyperbilirubinemia**, not folate depletion - Folic acid does NOT prevent hemolysis or reduce bilirubin acutely - It is a supportive measure for chronic management, not the "next step" in acute crisis ## Why Option 3 (Splenectomy) Is Wrong Splenectomy is **not indicated** for G6PD deficiency because: - G6PD hemolysis is **episodic**, triggered by oxidative stress; between episodes, RBC survival is normal - Splenectomy is reserved for conditions with **chronic, intrinsic RBC defects** (hereditary spherocytosis, hereditary elliptocytosis) - Removing the spleen increases infection risk (asplenic syndrome) without preventing future G6PD crises - The primary management is **trigger avoidance**, not organ removal ## Why Option 4 (Prophylactic Penicillin) Is Wrong Prophylactic penicillin is indicated for: - **Asplenic patients** (post-splenectomy or functional asplenia, e.g., sickle cell disease) - Patients with **recurrent bacterial infections** G6PD deficiency does NOT cause asplenia or immunodeficiency; prophylactic antibiotics are not indicated and may promote antibiotic resistance.
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