Oral Food Challenge Failures to Egg, Milk, and Peanut: An Evaluation of Doses, Proportion, and Time
Sunday, March 6, 2016
South Exhibit Hall H (Convention Center)
Girish V. Vitalpur, MD FAAAAI, Kirsten Kloepfer, MD MS, James Slaven, MS, Frederick E. Leickly, MD MPH FAAAAI
Rationale: Few studies have compared eliciting doses (ED) for failed oral food challenges (OFCs).  The time to failure (TTF) has also not been compared.  The aims of this study were to compare EDs in grams of food consumed, the serving proportions, and TTFs for failed OFCs to egg, milk, and peanut.

Methods: A retrospective chart review analyzed open OFCs to egg, milk, and peanut, performed at an academic pediatric allergy clinic, from 2008-2013.  Serving sizes for each food were 12 grams (egg), 16grams (milk), and 10grams (peanut).  Median EDs, ED10 (ED for 10% of failures), and TTF (time from first dose ingested to onset of symptoms) were compared. OFCs were offered when milk sIgE was < 1.0 kU/L; egg sIgE was < 0.6 kU/L; and peanut sIgE was < 0.35 kU/L. Extensively-heated egg and milk OFCs were excluded. Data were analyzed via SAS v9.3 (Cary, NC).

Results: There were 51 failures among 185 OFCs (27.6%) (11 milk; 27 egg; 13 peanut). Median doses for failure did not significantly differ (milk 1000mg [60-8000]; egg 1500mg [10-12000]; peanut 1000mg [100-2700]).  ED10s did not significantly differ (milk 60mg; egg 100mg; peanut 100mg).  Median proportion of a serving did not significantly differ (milk=12%; egg 25%; peanut 11%).  Median TTF did not significantly differ (milk 60 min [9-219]; egg 121min [9-360]; peanut 120 min [25-199]).

Conclusions: Even when the specific IgE suggests a low risk of reaction, failures still occur, and seem to occur at similar amounts of food exposure, similar proportions of food serving, and similar time frames.