What type of influenza (flu) vaccine is recommended for a patient with a history of egg allergy, specifically those who experience urticaria (hives) after egg consumption?

Influenza Vaccination for Patients with Egg Allergy Presenting with Hives

Any licensed, age-appropriate influenza vaccine can be administered to a patient who develops only hives after egg consumption, without any special precautions beyond standard vaccination protocols. 1

Current ACIP Recommendations (2018-2019 Season and Beyond)

The most recent ACIP guidelines represent a significant liberalization from earlier recommendations:

• Patients with hives-only egg allergy can receive any influenza vaccine (IIV, RIV4, LAIV4, or ccIIV4) that is otherwise appropriate for their age and health status 1
• No special observation period is required beyond the standard 15-minute post-vaccination monitoring recommended for all vaccines to assess for syncope 1
• No skin testing is necessary before vaccine administration 1
• No divided-dose protocols are needed 1

Evolution of Guidelines: Understanding the Change

Earlier 2013 guidelines were more restrictive, requiring:

• Administration by providers familiar with egg allergy manifestations 1
• 30-minute post-vaccination observation 1
• Preference for IIV or RIV over LAIV 1

However, the 2018 guidelines eliminated these restrictions after VAERS surveillance data from 2011-2013 showed no disproportionate reporting of allergic reactions or anaphylaxis in egg-allergic patients receiving influenza vaccines 1

Vaccine Options by Egg Protein Content

Egg-Free Option:

• RIV4 (Flublok Quadrivalent): Completely egg-free, manufactured using recombinant technology without eggs 1, 2, 3
• Approved for ages ≥18 years 2
• No contraindication for egg allergy of any severity 1

Minimal Egg Protein:

• ccIIV4 (Flucelvax Quadrivalent): Contains theoretical maximum of 1.7×10⁻⁸ μg/0.5 mL dose of egg protein 1
• Approved for ages ≥2 years 4
• Viruses propagated in mammalian cells, not eggs 1

Standard IIVs:

• Contain ≤1 μg/0.5 mL dose of ovalbumin 1
• Safe for hives-only egg allergy 1

Clinical Algorithm for Hives-Only Egg Allergy

Step 1: Confirm the allergy history

• Verify that reactions to eggs consisted only of urticaria (hives) 1
• Patients who can eat lightly cooked eggs (e.g., scrambled eggs) without reaction are unlikely to be truly allergic 1

Step 2: Select any age-appropriate vaccine

• Choose based on age indication, availability, and patient health status 1
• No preference for egg-free vaccines is necessary for hives-only allergy 1

Step 3: Administer in standard setting

• Any routine vaccination setting is appropriate 1
• No requirement for specialized allergy-trained personnel 1

Step 4: Standard post-vaccination monitoring

• 15-minute observation for syncope (standard for all vaccines) 1
• No extended 30-minute observation required 1

Critical Distinction: Severe Egg Allergy

For patients with more severe reactions (angioedema, respiratory distress, lightheadedness, recurrent emesis, or requiring epinephrine):

• Any age-appropriate vaccine can still be used 1
• Must administer in medical setting (hospital, clinic, health department, physician office) 1
• Supervision by provider capable of recognizing and managing severe allergic reactions is required 1

Common Pitfalls to Avoid

• Do not unnecessarily delay vaccination due to egg allergy concerns when only hives have occurred 1, 5
• Do not perform skin testing for hives-only egg allergy—this is outdated practice 1
• Do not use divided-dose protocols—these are no longer recommended 1
• Do not restrict to egg-free vaccines only—any age-appropriate vaccine is acceptable 1
• Do not confuse egg allergy with previous severe allergic reaction to influenza vaccine itself—the latter is an absolute contraindication to future vaccination 1

Absolute Contraindication

A previous severe allergic reaction (anaphylaxis) to influenza vaccine itself (not eggs) is a contraindication to future receipt of that vaccine 1, 4