Egg allergy and influenza vaccination

Many egg-allergic patients are unnecessarily restricted from receiving the influenza vaccine. Patients with suspected egg allergy who require seasonal or H1N1 influenza vaccination can pose a significant challenge and should be appropriately evaluated by an allergist/immunologist. In most cases, if the benefits are felt to outweigh the risks, precautionary measures are available that can enhance safe vaccine administration. A case of influenza vaccine management in a child with egg allergy is presented. Clinical characteristics, diagnostic testing, case management, and natural history are reviewed. Clinical Pearls and Pitfalls include: (1) Batch-to-batch variability of egg content in extant influenza vaccines necessitates an informed and cautious approach to vaccination of an egg-allergic individual. (2) Due to denaturation of some egg proteins through heating, tolerance of “baked egg” products may not predict tolerance of “native egg” proteins present in the influenza vaccine. (3) Intradermal skin testing with influenza vaccine diluted 1:10 may be irritating to the skin and result in false positive results. (4) If skin test to the vaccine is positive, vaccination may still be cautiously administered, if necessary, in a graded-dose protocol, as presented herein. (5) Most patients with egg allergy are likely to develop egg tolerance by late childhood.