What is the appropriate management for a 16-year-old female patient presenting with syncope and right arm numbness, with laboratory evidence of iron deficiency anemia?

Management of Iron Deficiency Anemia in a 16-Year-Old Female with Syncope and Right Arm Numbness

This patient requires immediate evaluation for the neurological symptoms (syncope and right arm numbness) while simultaneously initiating iron replacement therapy for confirmed iron deficiency anemia.

Diagnosis Confirmation

The laboratory values confirm iron deficiency anemia 1:

• Ferritin 22 ng/mL (diagnostic threshold <30 ng/mL for females >15 years) 1
• Iron saturation 19% (below the 20% threshold indicating iron deficiency) 1
• Low serum iron (63 μg/dL) with elevated TIBC (332 μg/dL) and UIBC (269 μg/dL) further support absolute iron deficiency 1

The ferritin level of 22 ng/mL is definitively diagnostic of iron deficiency in this adolescent female without need for additional confirmatory testing 1.

Urgent Neurological Evaluation Required

The syncope and right arm numbness are concerning symptoms that require immediate medical attention beyond iron deficiency management 2. While iron deficiency can cause lightheadedness and exercise intolerance, focal neurological symptoms like unilateral arm numbness warrant urgent evaluation for:

• Cerebrovascular events (though rare in this age group)
• Cardiac arrhythmias causing syncope
• Severe anemia-related cerebral hypoperfusion
• Other neurological conditions unrelated to anemia

The patient should undergo cardiovascular assessment (ECG, orthostatic vital signs) and neurological examination to exclude life-threatening causes of syncope 2.

Investigation for Underlying Cause

All adolescent females with confirmed iron deficiency anemia require evaluation for the source of iron loss 1:

Menstrual History (Most Common Cause)

• Heavy or prolonged menstrual bleeding is the leading cause of iron deficiency in reproductive-age females (38% have iron deficiency without anemia, 13% have iron-deficiency anemia) 2
• Document menstrual cycle length, duration, and heaviness 1, 3

Dietary Assessment

• Evaluate for inadequate dietary iron intake, vegetarian/vegan diet, or eating disorders 4, 2
• Borderline iron-deficient diets are common but should not preclude further investigation 1

Gastrointestinal Evaluation

• Celiac disease screening with tissue transglutaminase (tTG) antibody is mandatory - approximately 2-5% of patients with iron deficiency anemia have celiac disease 1
• Consider gastrointestinal blood loss if menstrual history is unremarkable 3
• NSAID use should be documented and discontinued if present 1

Additional Testing

• Complete blood count to assess hemoglobin level (not provided in your labs) 1
• C-reactive protein to exclude inflammatory conditions that could falsely elevate ferritin 4

Iron Replacement Therapy

First-Line: Oral Iron Supplementation

Initiate oral ferrous sulfate 60-120 mg elemental iron daily 1:

• For adolescent females, the CDC recommends 60 mg elemental iron daily 1
• Ferrous sulfate 325 mg tablets contain approximately 65 mg elemental iron 2
• Administer between meals to maximize absorption 1
• Alternate-day dosing may improve tolerability and absorption by avoiding hepcidin upregulation 1, 4

Expected response: Hemoglobin should increase ≥10 g/L (≥1 g/dL) within 2-4 weeks, confirming the diagnosis even if iron studies were equivocal 1.

Follow-Up Protocol

Repeat hemoglobin/hematocrit in 4 weeks 1, 4:

• If appropriate response (Hb increase ≥1 g/dL), continue iron therapy for 2-3 additional months to replenish iron stores 1, 3
• Recheck hemoglobin and ferritin after completing therapy 1
• Reassess approximately 6 months after successful treatment completion 1

When to Consider Intravenous Iron

IV iron is NOT typically first-line in adolescents but may be indicated if 1, 2:

• Oral iron intolerance (gastrointestinal side effects causing non-compliance) 1
• Failure to respond to oral iron after 4 weeks despite compliance 1
• Malabsorption conditions (confirmed celiac disease) 1
• Ongoing blood loss that cannot be controlled 1, 2

Non-Response to Oral Iron

If hemoglobin does not increase after 4 weeks of compliant oral iron therapy 1:

• Verify compliance and proper administration (between meals, no concurrent antacids/PPIs) 1
• Repeat iron studies including MCV, RDW, and ferritin 1
• Consider trial of IV iron (65% response rate vs 21% with continued oral iron in non-responders) 1
• Investigate for ongoing blood loss or malabsorption 3

Common Pitfalls to Avoid

• Do not delay neurological evaluation while treating anemia - syncope and focal neurological symptoms require urgent assessment 2
• Do not assume dietary deficiency alone - always screen for celiac disease in adolescents with iron deficiency anemia 1
• Do not use excessive iron doses - preparations with 28-50 mg elemental iron may improve compliance by reducing gastrointestinal side effects 4
• Do not continue long-term daily iron supplementation once ferritin normalizes - this is potentially harmful 4
• Do not skip follow-up testing - failure to document response may miss non-responders or alternative diagnoses 1

Long-Term Management

For adolescent females with recurrent iron deficiency due to heavy menstrual bleeding 4:

• Consider intermittent oral iron supplementation to maintain stores 4
• Monitor ferritin every 6-12 months 4
• Gynecological consultation for menstrual management may be appropriate 2