Reactions to Peanut during a Double-Blind Placebo Controlled Food Challenge (DBPCFC) for Enrolment in a Randomized Trial
Monday, March 5, 2018
South Hall A2 (Convention Center)
Adriana Chebar Lozinsky, Paxton Loke, MBBS, Kuang-Chih Hsiao, MBChB BHB DipPaed FR, Christine Axerald, Sigrid Pitkin, Marnie Robinson, MBBS DRANZCOG FRACP, EeLyn Su, MBBS FRACP, Anne-Louise Ponsonby, Patrick Quinn, MBBS FRACP, Dean Tey, MBBS FRACP, Michael O'Sullivan, MBBS FRACP FRCPA, Michael S. Gold, MBChB DCH MD FRACP F, Susan L. Prescott, BMedSc MBBS PhD FRAC, Katarina Jane Allen, MBBS BMedSc PhD FRAC, Francesca Orsini, Mimi L. K. Tang, MBBS PhD FAAAAI, And PPOIT003 Study Group
Rationale: Few studies have comprehensively examined reaction characteristics in a large cohort. We describe symptoms and eliciting doses during DBPCFC in children with peanut allergy. Predictors of cumulative reaction-eliciting dose and severity were also examined.

Methods: Children underwent a DBPCFC (4950mg peanut protein). Demographics, peanut sIgE, peanut skin prick test (SPT) and reaction characteristics were recorded. Associations between variables were investigated by correlation, linear and logistic regression analyses.

Results: 112 children completed DBPCFC; 7 did not react, 103 reacted to peanut but not placebo, and 2 reacted to both peanut and placebo. The median cumulative reaction-eliciting dose was 1200mg (IQR 560–2450). 23.4% reacted to ≤240 mg and 51.4% to ≥1200mg. Abdominal pain (68%) and vomiting (59.2%) were the most frequent symptoms. Anaphylaxis occurred in 21.4%. There was no association between reaction-eliciting dose and reaction severity. Peanut sIgE and SPT were negatively correlated to reaction-eliciting dose (p<0.001) but sIgE was the only predictor on regression analysis (p0.002). Peanut sIgE and SPT were not associated with and did not predict reaction severity.

Conclusions: Reaction-eliciting dose varied widely in this cohort of peanut allergic children, with the majority (76.6%) reacting to ≥560mg peanut protein. Severity of reaction was not related to dose at reaction and is difficult to predict. DPBCFC were equivocal or negative in 8.7% of children, supporting inclusion of DBPCFC at study entry to confirm eligibility in food immunotherapy trials.