Screening tests, such as skin tests (SPT) and serum IgE levels
can predict food allergic reactions but ultimately, feeding
patients the suspected allergic food is the only way of
confirming or ruling out a food allergy (oral food challenge).
Oral Food Challenges (click to enlarge the diagram). The double-
blind oral food challenge (OFC) is the best method from from
research perspective but the procedure can take upwards of 8
hours and is often impractical in most real-life settings. In a
recent JACI article, data was reviewed from 700 oral challenges
performed at a university-based pediatric allergy outpatient
clinic (Mount Sinai School of Medicine, New York) during 2
years. Patients were rarely challenged if the risk of reaction
was deemed to be greater than 50%. 19% of the challenges were
positive, i.e. elicited a reaction. Milk, peanut, wheat, and soy
most commonly elicited a reaction. Factors associated with
positive challenges included: - larger positive reaction on skin
tests - higher food-specific serum