How to manage generalized itch in a vegetarian patient with iron deficiency anemia?

Management of Generalized Itch in a Vegetarian with Iron Deficiency Anemia

Treat the iron deficiency anemia with iron replacement therapy, as this is the direct cause of the generalized pruritus and will lead to complete cessation of itching shortly after starting treatment. 1

Immediate Management

Iron Replacement Therapy

• Iron deficiency is the most common systemic cause of generalized pruritus, accounting for 25% of all patients with pruritus due to underlying systemic disease, and responds directly to iron replacement. 1, 2
• Iron replacement leads to complete cessation of pruritus very shortly after commencement of therapy in many cases. 1, 3
• Start with oral iron supplementation as first-line therapy using ferrous sulfate 325 mg daily or on alternate days to minimize gastrointestinal side effects. 4
• Alternatively, use preparations with 28-50 mg elemental iron content to prevent reduced compliance from gastrointestinal side effects. 5
• For vegetarians specifically, counsel on dietary iron sources including heme and free iron, and discuss enhancers (vitamin C, citric acid) and inhibitors (phytates, polyphenolics in plant foods) of iron absorption. 5, 6

Monitoring Response

• Repeat complete blood count and ferritin levels after 8-10 weeks to measure treatment success. 5
• Expect improvement in pruritus within days to weeks of starting iron replacement. 1

Essential Diagnostic Workup

Confirm Iron Deficiency

• Full blood count and ferritin levels should be checked in all patients with chronic generalized pruritus without rash. 1, 2
• Critical pitfall: Ferritin is an acute-phase protein and may be falsely elevated despite true iron deficiency. 1, 2
• If ferritin appears "normal" but iron deficiency is suspected, check serum iron and total iron binding capacity. 1
• Use a ferritin cut-off of 30 µg/L for adults over 15 years when considering treatment. 5

Investigate Underlying Cause in Vegetarians

• Inquire specifically about dietary patterns (vegetarian vs vegan), adequacy of iron intake, and use of iron absorption inhibitors. 1
• Test for tissue transglutaminase (TTG) antibodies to screen for celiac disease, which is a common cause of unexplained iron deficiency and impairs iron absorption. 1, 4
• Important caveat: IgA deficiency is relatively common and can cause falsely negative TTG readings. 1
• If TTG is abnormal, refer to gastroenterology for endoscopy and small bowel biopsy. 1
• Even with negative TTG, biopsy may still be indicated for unexplained iron deficiency. 1

Rule Out Other Causes of Generalized Pruritus

• Obtain liver function tests and urea/electrolytes to exclude hepatic and renal causes of pruritus. 7, 2
• Consider bile acids and antimitochondrial antibodies if liver disease is suspected. 7
• Review medications for potential drug-induced pruritus. 7

When to Consider Intravenous Iron

• Use intravenous iron if the patient has oral iron intolerance, poor absorption (confirmed celiac disease), or repeated failure of oral therapy. 5, 4
• Intravenous iron is also indicated for ongoing blood loss or chronic inflammatory conditions. 4

Long-Term Management for Vegetarians

• Patients with repeatedly low ferritin will benefit from intermittent oral iron supplementation to preserve iron stores. 5
• Repeat basic blood tests every 6-12 months to monitor iron stores in at-risk vegetarians. 5
• Do not continue long-term daily iron supplementation once ferritin normalizes, as this is potentially harmful. 5
• Provide ongoing dietary counseling about iron-rich plant foods and absorption enhancers. 5, 6

Symptomatic Relief While Awaiting Iron Repletion

• If pruritus is severe while waiting for iron replacement to take effect, consider emollients to maintain skin hydration and topical menthol preparations. 7
• Non-sedating antihistamines (fexofenadine or loratadine) may provide temporary relief but do not address the underlying cause. 7
• Avoid long-term sedative antihistamines due to potential dementia risk. 7, 2