A Review Of Peanut Oral Food Challenges In Patients With No Or Minimal Sensitization To Ara H2

Abstract

Ara h2 is considered the best predictor of systemic peanut reactions with some studies showing a negative predictive value of 100% using a cutoff value of <0.1 kU/L. However, the data are varied. We retrospectively examined the outcomes of 82 peanut oral food challenges (P-OFCs) conducted on patients with minimal or no Ara h2 sensitization. Patients had either no (Ara h2 ≤0.1 kU/L) sensitization (NS) or minimal (Ara h2 >0.1 but <0.35 kU/L) sensitization (MS) to Ara h2. Of 82 patients, 91% (75/82) had NS and 9% (7/82) had MS. The mean age of patients was 6.3 years (7 months to 29 years). Of all P-OFCs, 84% (69/82) had a pass outcome and 16% (13/82) had failed outcomes. Epinephrine use in failed challenges was 31% (4/13). Pass rate was 87% (65/75) in the subgroup with NS and 57% (4/7) with MS. Patients with NS were 5.7 times more likely to pass a P-OFC than those with MS (p=0.008). The odds of failing P-OFC was 4.9 times greater in patients with MS versus NS (p =0.058). In the NS group, mean skin prick test wheal of those failing P-OFCs was 4.1 mm (0-14 mm) and 3.2 mm (0-14 mm) for those passing P-OFCs. The majority of patients with no or minimal sensitization to Ara h2 pass P-OFCs (84%). Of those who fail challenges in this group, a substantial proportion require epinephrine (31%). The trend towards increased risk of P-OFC failure with minimal sensitization to Ara h2 warrants further exploration.