Hematology · USMLE Step 1 and Step 2

Iron Deficiency Anemia song

Iron Deficiency Anemia - Labs & Causes, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

Iron Deficiency Anemia

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Key points in this song10

Iron deficiency anemia is the most common cause of microcytic, hypochromic anemia worldwide, characterized by low MCV, low MCH, and elevated RDW due to anisocytosis.
Lab findings show low serum iron, low ferritin (earliest and most sensitive marker of iron depletion), high TIBC, and low transferrin saturation (below 20%).
The most common cause in premenopausal women is chronic blood loss from menstruation; in adult men and postmenopausal women, GI blood loss must be ruled out until proven otherwise.
Ferritin is an acute-phase reactant and can be falsely normal or elevated in the setting of infection or inflammation, masking true iron deficiency.
Stages of iron deficiency progress from depleted iron stores (low ferritin only) → iron-deficient erythropoiesis (rising TIBC, falling transferrin saturation) → frank iron deficiency anemia (low hemoglobin, microcytosis).
Classic clinical associations include pica (craving ice = pagophagia, dirt = geophagia), koilonychia (spoon-shaped nails), angular cheilosis, atrophic glossitis, and Plummer-Vinson syndrome (dysphagia from esophageal webs).
Treatment is oral ferrous sulfate 325 mg three times daily; reticulocytosis peaks at 7–10 days, hemoglobin should rise by 1 g/dL per week, and stores must be repleted for 3–6 months after hemoglobin normalizes.
IV iron is indicated when oral therapy fails, is not tolerated, or when there is ongoing blood loss that exceeds oral absorption capacity, such as in inflammatory bowel disease or chronic kidney disease.
Celiac disease is a high-yield cause of iron deficiency anemia refractory to oral supplementation due to malabsorption in the duodenum and proximal jejunum, where iron is preferentially absorbed.
Iron deficiency must be distinguished from anemia of chronic disease: ACD shows low iron, low TIBC, and normal-to-high ferritin, reflecting iron sequestration by hepcidin-mediated inhibition of ferroportin.