What is the treatment for severe itching after FCM?

Treatment of Severe Itching After FCM (Ferric Carboxymaltose)

For severe itching occurring 2 days after FCM administration, initiate treatment with oral H1-antihistamines (cetirizine, loratadine, or fexofenadine) combined with topical emollients containing urea or polidocanol, and consider adding topical corticosteroids if inflammatory skin changes are present. 1

Initial Management Approach

First-Line Treatment

• Start oral H1-antihistamines immediately: Use non-sedating agents such as cetirizine, loratadine, or fexofenadine for antipruritic effect 1, 2
• Apply topical emollients liberally: Use urea- or polidocanol-containing lotions to soothe pruritus, applying frequently throughout the day 1, 2
• Avoid aggravating factors: Instruct patients to avoid hot showers, excessive soap use, and alcohol-containing lotions which can worsen xerosis 1

Assess Severity and Skin Changes

If mild pruritus without skin lesions:

• Continue with oral antihistamines and emollients alone 1, 2
• Consider alternative antihistamines if first choice is ineffective: diphenhydramine, dimethindene, desloratadine, or clemastine 1

If moderate to severe pruritus with inflammatory skin changes:

• Add topical corticosteroids such as hydrocortisone 1% cream or prednicarbate cream to affected areas 1, 2
• Apply moisturizer after topical corticosteroid application to maintain skin hydration 2
• Use oil-in-water creams or ointments rather than alcohol-based preparations 1

Monitoring and Reassessment

• Reassess after 2 weeks to evaluate treatment response 1, 2
• Monitor for signs of secondary bacterial infection (impetiginization), which may require oral antibiotics 1
• If symptoms persist or worsen despite initial treatment, consider referral to dermatology for evaluation of alternative diagnoses or second-line therapies 2

Important Clinical Considerations

Common Pitfalls to Avoid

• Do not use sedating antihistamines long-term in elderly patients or those with renal impairment, as they may predispose to dementia 1
• Avoid cetirizine specifically in uremic pruritus if renal dysfunction is present, though this is less relevant for FCM-induced itch 1
• Do not over-dilute or under-treat: Patients may experience delayed hypersensitivity reactions to FCM, and symptoms can persist for 1-2 days after onset 1

When to Escalate Care

• If pruritus is accompanied by systemic symptoms (fever, hypotension, respiratory symptoms), consider delayed hypersensitivity reaction requiring urgent evaluation 1
• Severe, refractory pruritus not responding to first-line measures within 2 weeks warrants dermatology consultation 2
• Consider discontinuation of FCM for future doses if severe hypersensitivity reaction is confirmed 1

Patient Education

• Advise patients that mild delayed reactions can occur and may persist for 1-2 days 1
• Provide instructions to contact their physician if symptoms worsen or new symptoms develop 1
• Emphasize the importance of continuing emollient use even after symptom resolution to prevent recurrence 1, 2