What are the common causes of recurrent iron deficiency anemia in elderly females?

Common Causes of Recurrent Iron Deficiency Anemia in Elderly Females

In elderly females, recurrent iron deficiency anemia is most commonly caused by chronic gastrointestinal blood loss, which requires thorough investigation to identify underlying pathology, particularly gastrointestinal malignancies. 1

Gastrointestinal Causes

Upper GI Sources

• Peptic ulcer disease - A leading cause of chronic occult blood loss
• Erosive gastritis/duodenitis - Often associated with NSAID use
• Esophagogastric malignancies - Critical to identify due to mortality implications
• Atrophic gastritis - Leads to impaired iron absorption
• Helicobacter pylori infection - Associated with recurrent IDA

Lower GI Sources

• Colorectal cancer - Most common colonic lesion causing IDA in elderly 1
• Angiodysplasia - Vascular malformations that can cause intermittent bleeding
• Diverticular disease - May cause chronic occult bleeding
• Inflammatory bowel disease - Can cause both blood loss and malabsorption 1

Small Bowel Pathology

• Celiac disease - Common cause of malabsorption in the UK 1
• Small bowel tumors - Less common but important to identify
• Crohn's disease - Can affect any part of GI tract
• NSAID enteropathy - Medication-induced small bowel injury 1

Non-Gastrointestinal Causes

Medication-Related

• NSAID use - Causes gastric erosions and enteropathy 1, 2
• Anticoagulant therapy - Increases risk of GI bleeding 3
• Long-term PPI therapy - May impair iron absorption 2

Surgical History

• Previous gastrectomy - Reduces acid production needed for iron absorption 1
• Bariatric surgery - Common cause of recurrent IDA (affects ~25% of patients 2 years post-Roux-en-Y) 1, 2

Nutritional Factors

• Poor dietary iron intake - More common in elderly with limited diets 2
• Malnutrition - Often overlooked in elderly populations

Other Medical Conditions

• Chronic kidney disease - Associated with iron deficiency 2, 4
• Congestive heart failure - 37-61% have iron deficiency 4
• Chronic inflammatory conditions - Impair iron utilization 4

Diagnostic Approach for Recurrent IDA

1. Confirm true iron deficiency:

   • Serum ferritin <30 ng/mL (or <100 μg/L in presence of inflammation) 1, 2
   • Transferrin saturation <20% 4

2. Bidirectional endoscopy:

   • Upper GI endoscopy and colonoscopy are first-line investigations 1, 2
   • Should be performed even if previous investigations were negative if >2 years have passed 1

3. Small bowel evaluation:

   • Consider capsule endoscopy if bidirectional endoscopy is negative 1
   • Particularly high yield in recurrent unexplained IDA 1

4. Additional investigations:

   • Consider CT imaging of abdomen/pelvis
   • Evaluate renal tract (renal cell carcinoma association) 1
   • Screen for celiac disease 2

Management Considerations

• Monitor response to treatment:

  • Check hemoglobin after 4 weeks of iron replacement 2
  • Monitor periodically (every 6 months initially) after restoration of Hb and iron stores 1

• Long-term iron replacement:

  • Appropriate when cause is unknown or irreversible 1
  • Consider parenteral iron in cases of malabsorption or intolerance to oral iron 1, 4

• Address underlying cause:

  • Treat H. pylori if present 2
  • Consider discontinuing NSAIDs if possible 3
  • Manage inflammatory conditions appropriately 1

Important Caveats

• Multiple pathologies may coexist in 1-10% of cases, particularly in elderly patients 1
• A history of GI surgery should not preclude search for other causes 1
• Even with comprehensive investigation, a small percentage of cases remain unexplained 1
• Recurrent IDA after negative initial workup warrants repeat investigation, not just continued iron replacement 1

Remember that in elderly females with recurrent IDA, gastrointestinal malignancy must be excluded before attributing to other causes, as early detection significantly impacts mortality outcomes.