Flare Size in Skin Prick Test May Predict Oral Food Challenge Outcomes

Larger skin flare results in pediatric patients correlated to failing certain oral food challenges, but were not predictive of requiring epinephrine, according to the results of a recent study presented at the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting, held virtually from November 13 to 15.

Researchers conducted a retrospective review of egg, cow’s milk, and peanut oral food challenge results at a large pediatric institution during a 3-year period. Mann Whitney testing was used to compare flare size results from passing and failed oral food challenges.

Of the 752 oral food challenges reviewed, the overall pass rate was 55%. When skin flare size was evaluated, failed oral food challenges had significantly larger flares than passing oral food challenges (median failed, 20 mm vs median passed, 12 mm; P <.0001). Furthermore, the flare size appeared consistent between individual foods (egg: failed, 17.5 mm vs passed, 11.5 mm; P <.0001; cow’s milk: failed, 20 mm vs passed, 12 mm; P =.0007; and peanut: failed, 20 mm vs passed, 14 mm; P <.0001). However, flare size was not associated with requiring epinephrine treatment. 

“[Skin prick test] flare size were significantly larger in children who failed [oral food challenge] to egg, cow’s milk, and peanut,” the researchers wrote. “Flare size, in addition to wheal, may serve as a valuable predictive indicator for [oral food challenge] outcomes.”

Reference

Harrison H, Spergel J, Capucilli P. Significance of skin prick test flare measurements in predicting oral food challenge outcomes. Presented at: the American College of Allergy, Asthma & Immunology (ACAAI) Annual Scientific Meeting (Virtual Experience); November 13-15, 2020. Abstract P304.