Outcomes of oral food challenges in a real-world setting, with predictors of outcomes

Oral food challenge (OFC) remains the reference standard for food allergy (FA) diagnosis.

This study reports a single-center observational experience with all OFCs conducted over 3 years.

All OFCs performed at an outpatient office were tracked. The OFCs were conducted without strict prespecified inclusion or exclusion criteria. Demographic information along with results of diagnostic testing and results of the OFCs were recorded.

A total of 1132 OFCs were performed, with a median age of 4 years (interquartile range = 2.0-10.0). Of the 1132 OFCs, 862 (76.1%) tolerated the food, whereas 232 (20.5%) experienced a reaction, and 38 (3.4%) did not complete the OFC because of food refusal. The highest percentage of tolerated food was shellfish (91.1%), with the lowest percentage of tolerated food being baked egg (66.1%). There were 66 (5.8%) OFCs that were deemed to be high risk, of which 35 (53.0%) tolerated the food. More than 50% of reactions occurred on the first or second dose, with the most common clinical symptom being urticaria or angioedema, with 29.2% of reactions treated with epinephrine. There were several factors that predicted tolerating an OFC, including the food challenge, the reason for food avoidance, older age at the time of OFC and less reactive skin prick testing, and lower food-specific immunoglobulin E levels.

Certain factors can predict tolerating an OFC, and even those considered to be high risk can be safely completed in an outpatient setting, with most tolerating the food, and most reactions not requiring treatment with epinephrine.