D1.214 - Food Allergy:Even in doubt, Challenge Test

Egg allergy is a common food allergy, with a prevalence in children aged 0-5 years ranges from 0.2% to 8.9% according to published literature. It is more prevalent in infants and toddlers, with most children outgrowing the allergy by age 5. Symptoms range from mild skin reactions to severe anaphylaxis, and diagnosis is confirmed through skin tests, specific IgE testing, and controlled provocation tests.

An 11-month-old child presents in October 2024, one hour after consuming scrambled eggs, with an episode of exanthem on the auricular regions and on the upper trunk, without other symptoms. The patient was administered 1 ml of Polaramine with improvement, and then presented to the SURG (Urgent Care Center), where they were additionally given Stilsona, and observed for 1 hour with a good response.

The patient had previously tolerated cooked egg without any incidents.

Skin tests with egg white were positive. Total IgE: 137, Specific IgE to whole egg: 0.75, Egg white: 0.74, Ovalbumin: 0.12, Ovomucoid: 0.28, Conalbumin: 0.1, Egg yolk: 0.19, Lysozyme: 0.85.

December 2024: Prick-prick test with tortilla was negative. Controlled provocation test with tortilla: 50 minutes after ingestion, hives began on the abdomen, requiring the administration of Polaramine. As the urticaria progressed to generalized hives, including the face, oral corticosteroids were administered without resolution. As the child began showing signs of lethargy and significant irritability, adrenaline was administered, and the condition resolved.

March 2025: Prick-prick test with 6 egg-cake, tortilla, and cooked egg was positive only for cooked egg. Controlled provocation test with a small piece of tortilla: immediate good tolerance.

The patient has reintroduced foods containing trace amounts of egg, such as pasta.

The food challenge test is essential for making accurate, evidence-based decisions regarding food allergies in children, ensuring the avoidance of the suspected food when confirmed the diagnosis, which must include a challenge test if the skin or blood test are negative.

To reintroduce a suspected food after avoidance must be done in the presence of an Allergy Specialist during an oral challenge test.