A 38-year-old woman from rural Maharashtra presents with a 6-month history of progressive fatigue, dyspnea on exertion, and palpitations. She reports heavy menstrual bleeding for the past 2 years. On examination: pallor of conjunctivae and nail beds, heart rate 102/min, BP 110/70 mmHg. Laboratory investigations: Hb 7.2 g/dL, MCV 62 fL, MCH 18 pg, RBC count 5.8 × 10¹²/L, serum iron 28 µg/dL (normal 60–170), ferritin 8 ng/mL (normal 12–200), TIBC 420 µg/dL (normal 250–425), transferrin saturation 6.5% (normal 20–50%). Peripheral blood smear shows microcytic hypochromic RBCs with occasional target cells. What is the most appropriate next step in management?

Explanation

## Clinical Diagnosis **Key Point:** This patient has iron deficiency anemia (IDA) confirmed by the classic triad of low serum iron, low ferritin, and elevated TIBC with reduced transferrin saturation. ### Diagnostic Criteria Met | Parameter | Value | Interpretation | |-----------|-------|----------------| | Hb | 7.2 g/dL | Moderate anemia | | MCV | 62 fL | Microcytic (< 80 fL) | | Serum iron | 28 µg/dL | Low (normal 60–170) | | Ferritin | 8 ng/mL | Low (normal 12–200) | | TIBC | 420 µg/dL | Elevated (normal 250–425) | | Transferrin saturation | 6.5% | Severely reduced (normal 20–50%) | | Peripheral smear | Microcytic hypochromic RBCs, target cells | Consistent with IDA | **High-Yield:** Ferritin < 15 ng/mL is virtually diagnostic of iron deficiency; combined with elevated TIBC and low serum iron, it confirms absolute iron deficiency. ### Management Algorithm ```mermaid flowchart TD A[Iron Deficiency Anemia Confirmed]:::outcome --> B{Source of iron loss?}:::decision B -->|Menstrual bleeding| C[Gynecological referral + Oral iron]:::action B -->|GI bleeding| D[GI endoscopy + Oral iron]:::action B -->|Dietary insufficiency| E[Dietary counseling + Oral iron]:::action C --> F[Ferrous sulfate 200 mg TDS]:::action D --> F E --> F F --> G[Recheck Hb in 4-6 weeks]:::decision G -->|Hb rising| H[Continue iron, address source]:::action G -->|Hb static/falling| I[Investigate for ongoing loss or malabsorption]:::decision I -->|Persistent loss| J[IV iron or transfusion if Hb < 5]:::action ``` ### Why Oral Iron First? 1. **First-line therapy** for uncomplicated IDA [cite:Harrison 21e Ch 397] 2. **Cost-effective** and well-tolerated at lower doses 3. **Adequate response expected** in 4–6 weeks if compliance is good 4. **Source identification critical**: Heavy menstrual bleeding requires gynecological evaluation to exclude structural pathology (fibroids, adenomyosis) or coagulopathy **Clinical Pearl:** In women with IDA and menorrhagia, always exclude uterine pathology and assess for coagulation disorders (von Willebrand disease, platelet dysfunction) before attributing all bleeding to heavy periods alone. ### Dosing & Monitoring - **Ferrous sulfate 200 mg TDS** (provides ~60 mg elemental iron per dose) - Expected Hb rise: **1–2 g/dL per month** if absorption is normal - Recheck Hb at **4–6 weeks**; if no rise, suspect malabsorption or ongoing loss - Continue iron for **3–6 months** after Hb normalizes to replete iron stores **Warning:** GI side effects (nausea, constipation, abdominal discomfort) occur in 10–30% of patients on oral iron; consider dose reduction or alternate-day dosing if intolerant.