Egg Allergy

Background

• Egg allergy is a specific and reproducible immune response (typically immunoglobulin E [IgE] mediated) occurring after exposure to egg protein.
• Likely risk factors for egg allergy include asthma, allergic rhinitis, or atopic dermatitis.
• The mean age of onset is 10 months, usually coinciding with egg introduction into the infant diet.
• Egg allergy generally resolves in childhood.
• Exclusive breastfeeding in the first 4-6 months of life and early introduction of egg into the infant diet may decrease the risk of egg allergy.

Evaluation

• Perform a careful history (including a family history) and thorough physical examination on any patient suspected of an egg allergy.
• Suspect IgE-mediated egg allergy in children with a clinical history of allergic symptoms and/or signs of anaphylaxis occurring within minutes or hours of ingesting egg protein or food with suspected egg protein.
  • Consider egg-specific skin prick and/or serum IgE testing only in patients with a convincing history.
  • Consider an oral food challenge in patients with an unclear history of allergic symptoms or with negative or borderline IgE testing.
  • Perform a blind food challenge if the diagnosis of egg allergy is unclear after an oral food challenge.
• Suspect non- or mixed-IgE-mediated egg allergy in patients with delayed or chronic symptoms (≥ 2 hours to weeks) after ingesting suspected food allergen; physical findings of failure to thrive, dermatitis herpetiformis, and/or common comorbid conditions such as moderate-to-severe atopic dermatitis increase suspicion of non- or mixed-IgE-mediated reactions.
• Consider an egg elimination diet in patients with an unclear or uncertain history of clinical reactivity to suspected egg allergy.
• Consider endoscopic evaluation and biopsy in patients with suspected non- or mixed-IgE-mediated egg allergy.

Management

• Counsel patients or parents to avoid all egg products; some patients may be able to tolerate eggs in baked products.
• Provide self-injectable epinephrine to patients with a history of anaphylaxis.
• Emergency management with medications may be required after accidental egg allergen ingestion.
• Treat patients with acute reactions requiring epinephrine with prednisone 1-2 mg/kg/day (up to 60 mg/day) and an antihistamine such as diphenhydramine 1-2 mg/kg (up to 50 mg/dose).
• Consult a dietitian for
  • patients with multiple food allergies
  • children on elimination diets that might affect growth
  • documented poor growth