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Dictionary of Allergies .. Food challenge

Food challenge

10% to 20% of the population sees itself as suffering from food allergy, yet genuine, immune-mediated food allergy is suspected by patients and their physicians far more often than it is actually shown to be present. The unfounded suspicion of an IgE-mediated food allergy can substantially impair a patient's quality of life through needless dietary restriction and the accompanying anxiety. On the other hand, an IgE-mediated food allergy that has gone undiagnosed or that has not been taken seriously can manifest suddenly with anaphylaxis, which may be life-threatening.[1]. Food challenge is the consumption of suspected food for the induction of allergic symptoms in  increasing amounts at fixed intervals under the observation of a  physician specialist in allergy.

The patient is taking by mouth gradually increasing doses of the suspected food at 10-30 minutes until a reaction occurs or a normal amount of the food is received  without causing symptoms. Oral food challenges are essential to the diagnosis of food allergy. There are three types of oral food challenges: 1. Double-blind placebo-controlled food challenge (DBPCFC). 2.Open food challenge (OFC) and 3. Single-blind placebo-controlled food challenge (SBPCFC).

Oral food challenges are procedures conducted by allergists/immunologists to make an accurate diagnosis of immediate, and occasionally delayed, adverse reactions to foods. The timing of the challenge is carefully chosen based on the individual patient history and the results of skin prick tests and food specific serum IgE values. The type of the challenge is determined by the history, the age of the patient, and the likelihood of encountering subjective reactions.

The food challenge requires preparation of the patient for the procedure and preparation of the office for the organized conduct of the challenge, for a careful assessment of the symptoms and signs and the treatment of reactions. The starting dose, the escalation of the dosing, and the intervals between doses are determined based on experience and the patient's history. The interpretation of the results of the challenge and arrangements for follow-up after a challenge are important. A negative oral food challenge result allows introduction of the food into the diet, whereas a positive oral food challenge result provides a sound basis for continued avoidance of the food [2].

References

1. Seitz CS, Pfeuffer P, Raith P, Bröcker EB, Trautmann A. Food allergy in adults: an over- or underrated problem?

Dtsch Arztebl Int. 2008 Oct;105(42):715-23. Epub 2008 Oct 17

2. Nowak-Wegrzyn A, Assa'ad AH, Bahna SL, Bock SA, Sicherer SH, Teuber SS; Adverse Reactions to Food Committee of American Academy of Allergy, Asthma & Immunology. Work Group report: oral food challenge testing. J Allergy Clin Immunol. 2009 Jun;123(6 Suppl):S365-83

Γκέλης Ν.Δ. - Λεξικό Αλλεργίας - Εκδόσεις ΒΕΛΛΕΡOΦΟΝΤΗΣ - Κόρινθος 2013

Gelis Ν.D. - Dictionary of Allergies - VELLEROFONTIS Publications - Corinth 2013