COMPARING SYMPTOM SEVERITY BETWEEN BASELINE AND 1-YEAR ORAL FOOD CHALLENGES IN PEANUT ORAL IMMUNOTHERAPY

Abstracts: Poster Sessions / Ann Allergy Asthma Immunol 121 (2018) S22−S62

Results: Assuming a 10-fold increased fatality risk from nonimmediate EMS activation and 12% risk for biphasic reactions, a context-sensitive approach of EMS activation decreased costs with minimal absolute risk. In the setting of a food allergic reaction that resolved immediately and completely with prompt epinephrine treatment, the per-patient fatality rate was 1.2 £ 106 vs. 1.9 £ 10-6 for immediate vs context sensitive EMS activation. Reflex activation cost $142,943,447 per quality-adjusted life year and $1,349,335,651 per death prevented. Cost rose to $321,625,534 per life-year saved ($3,035,454,848 per death prevented) assuming a 5-fold increased fatality risk, but fell to $12,997,173 per life-year saved ($122,689,936 per death prevented) assuming a 100-fold increased fatality risk. Conclusions: In children with immediate and complete resolution of food allergic reactions following prompt epinephrine use a context-specific “wait and see” approach to EMS activation can be considered.

Sensitivity analysis denotes that early EMS care after epinephrine use becomes costeffective when the risk of fatality from the “wait and see” approach exceeds a 500-fold increase together with a likely probability that care would be needed exceeding 75%. Cost-effective care is considered to cost less than $100,000 per life-year saved.

P310 TREATMENT SATISFACTION WITH AR101 PEANUT ALLERGY ORAL IMMUNOTHERAPY: A MIXED METHODS STUDY A. Assa'ad*,1, M. Welch2, S. Acaster3, K. Gallop3, J. DeVries3, N. Griffin4, K. Brown4, J. Bird5, 1. Cincinnati, OH; 2. San Diego, CA; 3. London, United Kingdom; 4. Brisbane, CA; 5. Dallas, TX Introduction: This study aimed to explore treatment satisfaction and impact on quality of life (QOL) post-participation in a clinical trial of an oral immunotherapy treatment, AR101, for peanut allergy (PA). Methods: Following a protocol amendment, a subset of participants and their parents, completing a phase 2 open-label extension trial of AR101 (ClinicalTrials.gov Identifier: NCT02198664) were asked to complete two treatment satisfaction questionnaires and an optional telephone interview. The TSQM-9 (Treatment Satisfaction Questionnaire for Medication), completed by parents, was scored on a 0-100 scale. A customized treatment-specific exit questionnaire (EXIT) assessed palatability, convenience, adherence, and treatment experience. EXIT, completed by parents and participants, was scored on 5or 7-point Likert scales. Interview data were analyzed using thematic analysis. Results: Nineteen parents and eighteen children completed EXIT; nine subjects were interviewed. Twenty parents completed the TSQM-9. The mean time in study was 3.5 years. TSQM-9 scale scores

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showed moderate-to-high levels of treatment satisfaction (effectiveness: 76; convenience: 58; satisfaction: 86). EXIT showed that most patients almost always/always took the drug exactly as instructed (100% parents; 86% children). All parents and 86% of children felt the advantages of therapy with AR101 outweighed the disadvantages. The qualitative analysis identified five key areas of QOL impacted by PA: emotional functioning, social and leisure activities, daily activities, relationships, and independence/supervision. All areas improved after trial participation. Conclusions: This is the first cohort of patients to be treated longterm with AR101. These results show moderate-to-high levels of treatment satisfaction and improved QOL following AR101 treatment.

P311 ATOPY PATCH TESTING IN PEDIATRIC PATIENTS WITH PROTON PUMP NONRESPONSIVE EOSINOPHILIC ESOPHAGITIS Z. Treyster*,1, C. Patel1, M. Cheng2, P. Ponda1, 1. Great Neck, NY; 2. New Haven, CT Introduction: The role of atopy patch testing (APT) in Eosinophilic Esophagitis (EoE) remains controversial with no clear guidance for utility in the Food Allergy Practice Parameters. This exploratory study examines the use of APT in pediatric patients with EoE. Methods: A retrospective chart review from 08/2017 to 06/2018 was conducted at a large academic Allergy/Immunology Division. Pediatric patients with a diagnosis of EoE who underwent APT in conjunction with skin prick testing to guide food elimination were identified. Results of APT and response to dietary elimination were evaluated using descriptive statistics. Results: 45 patients, ages 2 to 18 years, were identified with initial screening. 5 patients had APT prior to second biopsy showing PPI responsiveness and were excluded. Three patients were lost to follow-up. 1 patient was diagnosed with an eating disorder and did not undergo food elimination. 5 additional patients have follow-up endoscopy pending. A total of 31 patients were included in final assessment: 23 males and 8 females, average age 9 years. Of the 31 patients, 1 had improvement on biopsy that could be uniquely attributed to APT. The remaining 30 patients (97%) had APT that was not useful in identification of triggering foods. Conclusions: In our sample of pediatric EoE patients, APT was not useful in identifying foods for removal. Given the productivity loss for both patients and parents as well as the increased financial costs of patch tests and three additional visits, guidelines on EoE management should be adapted to more strongly discourage APT for identification of triggering foods.

P312 COMPARING SYMPTOM SEVERITY BETWEEN BASELINE AND 1-YEAR ORAL FOOD CHALLENGES IN PEANUT ORAL IMMUNOTHERAPY S. Anvari*, A. Anagnostou, D. Tran, C. Davis*, Houston, TX Introduction: Peanut oral immunotherapy (POIT) trials have examined the adverse effects of double blind placebo-controlled food challenges (DBPCFC) with a cumulative top dose of 5000mg of peanut protein following maintenance dosing. Comparison of the severity of adverse reactions during DBPCFC beyond 5000mg of peanut protein between baseline and 1 year have not yet been evaluated. Methods: In a single center phase 1 clinical trial of POIT, patients underwent a baseline DBPCFC, subsequent build-up daily dosing to 3900mg of peanut protein over 1-year, followed by a second DBPCFC to a cumulative dose of 26,225mg. Total symptom score (TSS) was determined by the sum of the individual system symptom severity

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Abstracts: Poster Sessions / Ann Allergy Asthma Immunol 121 (2018) S22−S62

scores during the challenge reaction (1=mild, 2=moderate, 3=severe). Challenge TSS and system scores were compared at baseline and after 1 year of treatment by the Kruskal-Wallis test. Results: In 12 POIT subjects, DBPCFC symptoms decreased in 83% of patients after 1 year of therapy when compared to baseline. Mean TSS was 8.6 (4-16) at baseline and 4.5 (0-10) at 1 year (p Conclusions: Overall, in this POIT trial with 3900mg maintenance dosing, symptoms during a DBPCFC beyond 5000mg significantly improved from baseline to 1 year. Specifically, respiratory and gastrointestinal symptom severity decreased. After high-dose POIT, most patients experience reduced severity of allergic reactions to peanut.

P313 PHYSICIAN DIAGNOSIS OF ADULT FOOD ALLERGY G. Peirats Moore*,1, A. Chadha1, C. Warren2, J. Jiang1, B. Smith1, R. Gupta1, 1. Chicago, IL; 2. Los Angeles, CA Introduction: Food allergy (FA) is a life-threatening health condition that continues to increase in prevalence, yet knowledge regarding diagnosis and management of adult FA is limited. As a result, the objective of this study is to describe physician diagnostic practices of FA in adults. Methods: A survey was administered via web and telephone to a sample of US households between 2015-2016, providing parent parent-proxy responses for 40,443 adults. Stringent symptom criteria were developed with FA experts to distinguish respondents with “convincing” FA from those with similar conditions. Post stratification-weighted proportions were estimated to compare FA diagnosis characteristics by allergy type. Results: Approximately 50% (95% CI: 48.6-51.9) of convincing adult FA were not diagnosed by a physician. Physician diagnosis was significantly higher for males, adults with seasonal allergy, severe FA, and multiple FA. In families that earned less than $50,000, adults were significantly less likely to receive a physician diagnosis, whereas in families that earned between $50,000 and $100,000, adults were more likely to receive a physician diagnosis. Of physician-diagnosed FA, 70.2% (95% CI: is 67.9-72.5) were evaluated with a skin prick test, 47.4% (95% CI: 44.9-49.8) with an IgE test, and 30.3% (95% CI: 28.132.6) with an oral food challenge. Conclusions: Adults with convincing FA are not frequently receiving physician diagnoses. This suggests a higher perceived burden of FA that may result in unnecessary avoidance of food. and impaired quality of life.

P314 EGG ALLERGY IN US CHILDREN W. Samady*,1, R. Das1, J. Ross1, C. Warren2, J. Jiang1, B. Smith1, R. Gupta1, 1. Chicago, IL; 2. Los Angeles, CA Introduction: Egg allergy is common in young children ( Methods: A randomized, cross sectional survey was administered to 53,575 US households from October 2015 and September 2016, resulting in parent-proxy responses for 38,408 children. Data was analyzed in regard to demographics, symptoms, diagnosis, and comorbid conditions. Adjusted models were estimated to examine association of these characteristics with odds of egg allergy. Results: Overall prevalence of convincing egg allergy was 0.9% in all children and 1.3% of young children. Of those with egg allergy, 35.6% tolerate baked egg, 63.9% had >1 food allergy, and 29.3% have peanut allergy specifically. Egg allergy was more common among Black children (23.4% (13.1-38.4 vs. 13.2% (12.3-14-2)). Egg allergic children were more likely to have asthma (46.5% (35.8-57.4)), eczema (19% (12.2-28.2)), and allergic rhinitis (38.2% (30.7-46.4)). Severe allergic symptoms include: throat tightening (14.2%), wheezing (11.5%), and hypotension (11%). Physician diagnosed egg allergy occurred in 72.2%

of those with convincing allergy, with oral food challenges completed in 20.1%. Conclusions: Egg allergy is common among young children, and over one third of patients with egg allergy can tolerate baked egg. Efforts to increase physician diagnosis of egg allergy, including evaluation for baked egg, can significantly improve quality of life.

P315 PARENT REPORT OF PHYSICIAN DIAGNOSIS IN PEDIATRIC FOOD ALLERGY: AN UPDATE A. Chadha*,1, G. Peirats Moore1, C. Warren2, J. Jiang1, B. Smith1, R. Gupta1, 1. Chicago, IL; 2. Los Angeles, CA Introduction: Food allergies (FA) are a significant health concern for children in the United States, yet access to proper diagnosis and management can be limited. This study aims to characterize current childhood FA diagnosis practices in the US. Methods: A survey was administered via web and telephone to a sample of US households between 2015-2016, providing parent parent-proxy responses for 41,341 children. Stringent symptom criteria were developed with FA experts to distinguish respondents with “convincing” FA from those with similar conditions. Post stratification-weighted proportions were estimated to compare FA diagnosis characteristics by allergy type. Results: Approximately 39% (95% CI: 35.6-42.4) of convincing FA was not physician diagnosed. For families earning between $25,000 and $50,000, children were significantly more likely to not have received a physician diagnosis. Among physician-diagnosed FA, 68.2% (95% CI: 63.6-72.4) were evaluated with a skin prick test, 50% (95% CI: 46.254.7) with an IgE test, and 25% (95% CI: 21.2-29.3) with an oral food challenge. Rates of physician diagnosis differed by allergen with 81% of convincing peanut allergies physician diagnosed compared to under 55% of convincing milk, fin fish, wheat, and soy allergies. Odds of physician diagnosis were significantly higher for children with eczema, asthma, and seasonal allergy. Conclusions: These data suggest that children with convincing FA are often not receiving a proper diagnosis. It is critical we determine barriers to physician diagnosis of FA to ensure the best care and management of these children.

P316 PREVALENCE AND CORRELATES OF FOOD ALLERGY AMONG MEDICAID-ENROLLED U.S. CHILDREN L. Bilaver*, J. Szkodon, J. Fierstein, O. Negris, S. Kohli, R. Gupta, Chicago, IL Introduction: Previous research finds racial and socioeconomic disparities in the prevalence and economic impact of childhood food allergy (FA). The purpose of this study is to present a comprehensive baseline of the prevalence of FA among Medicaid-enrolled children in 2012 in the United States. Methods: Patient-level data from the Medicaid Analytic Extract (MAX) files were obtained under a data use agreement with the Centers for Medicare and Medicaid Services. The current study uses data from all 50 states and the District of Columbia in 2012. The target population (n=23,825,160) was limited to children ages 0-19 who were enrolled in the Medicaid program (and not Medicare) for all 12 months of 2012. Children with ICD-9 CM codes specific for FA were identified in outpatient and inpatient claims. Multiple logistic regression was used to measure the adjusted odds of FA by child characteristics. Results: Overall prevalence of FA was 0.94% with Nevada having the lowest rate (0.25%) and Pennsylvania having the highest (1.83%). FA prevalence was higher than the U.S. average among children