Review of 400 consecutive oral food challenges to almond

Background: Diagnosis of almond allergy is complicated by a high rate of false-positive test results. Accurate diagnosis of almond allergy is critical because almond is a source of nutrition and milk products for children with other food allergies. Objective: We reviewed the outpatient almond oral food challenges (OFCs) performed at our institution to analyze the pass rate and identify variables that predict OFC outcome. Methods: We reviewed all almond OFCs performed at our pediatric, university-based outpatient practice between October 2015 and July 2017. Oral food challenge details, including dosing, reactions, and treatments, as well as demographic, clinical, and laboratory data, were compiled. Statistical analysis was performed using the Fisher's exact and Student's t tests. Results: We identified 400 patients who underwent consecutive almond OFCs. Of these, 375 passed (93.8%, median sIgE 1.41 kU_A/L, mean skin prick test [SPT] wheal 3.23 mm), 16 failed (4.0%, sIgE 2.54 kU_A/L, SPT 5.0 mm), and 9 were indeterminate (2%, sIgE 3.33 kU_A/L, SPT 5.0 mm). Among children who reacted, pruritus was the most common symptom. Only 2 children had reactions that required epinephrine. No difference was seen in demographics or allergic comorbidities between those who passed and failed. Conclusion: Among patients in our cohort, the probability of passing an almond OFC was 94%. Although increasing almond sIgE level and SPT wheal size correlated with OFC failure, the pass rate remained greater than 95% for patients with sIgE up to 10 kU_A/L and SPT wheal size up to 5 mm. Among the patients who had a reaction to almond, anaphylaxis was uncommon. Our data support that performing outpatient OFCs to almond is safe for select patients.