🔍 Pallor & Anemia: Diagnostic Approach
📌 Pathophysiologic Mechanisms
• Acute blood loss
• Impaired RBC production (underproduction)
• Increased RBC destruction (hemolysis)
• Anemia of inflammation/chronic disease
🧪 Key Labs & Indices
• MCV: microcytic (<70 fL + age), normocytic, macrocytic
• Reticulocyte count (corrected)
• RDW: elevated in iron deficiency, normal in thalassemia trait
• Peripheral smear: morphology clues (spherocytes, sickle cells, schistocytes)
⚠️ Red Flags
• Pancytopenia → aplastic anemia, leukemia
• Severe anemia + bruising/petechiae → malignancy
• Macrocytic anemia + neutropenia → Fanconi/Diamond-Blackfan
• Hemoglobinuria, jaundice → acute hemolysis
🩸 Common Diagnoses
• Iron deficiency (most common nutritional)
• Thalassemia trait (microcytosis, normal RDW, elevated RBC count)
• Hereditary spherocytosis (spherocytes, positive family history)
• Sickle cell disease (sickled cells, HbSS)
• G6PD deficiency (acute hemolysis with oxidant stress)
💡 Algorithm: Corrected reticulocyte count <2% → underproduction (evaluate MCV). Microcytic → iron deficiency, thalassemia, lead, chronic disease. Normocytic → bone marrow failure, TEC, renal. Hemolytic → reticulocytosis + elevated LDH/indirect bilirubin.