Tracy Gonzalez, RN, BSN2, Tiffany Wong, MD, FRCPC2, Kyla J. Hildebrand, MD, FRCPC, MScCH (HPTE)2, and Edmond S. Chan,. MD, FRCPC2; 1Division of ...
AB252 Abstracts
793
Cutaneous Exposure to Peanut Oil Induces Systemic and Pulmonary Peanut Hypersensitivity Reaction
Shira Benor1,2, Laliv Kadar1, Shmuel Kivity, MD1, and Sheila Langier1; Tel Aviv Sourasky Medical Center, Tel Aviv, Israel, 2Sakler school of Medicine, Tel Aviv University, Tel Aviv, Israel. RATIONALE: The prevalence of peanut allergy is constantly increasing in children. Atopic dermatitis is a major risk factor for developing food allergy, and it has been suggested that exposure to peanut allergens through a disrupted skin barrier is a potential cause of peanut allergy. Some bath oils and skin creams used for treating atopic dermatitis contain peanut oil. Our aim was to investigate if cutaneous application of peanut oil caused a systemic or respiratory allergic response to peanut in this animal model. METHODS: Nine BALB/c mice underwent cutaneous sensitization with 50mL of peanut oil, or PBS control. Ten days after the last exposure mice were challenged with 5mg intranasal peanut protein. Bronchial alveolar fluid (BALF) was collected for cytologic studies and measurement of cytokine levels. Sera was collected for IgE measurement. RESULTS: Peanut oil sensitization increased leukocyte, eosinophil counts and IL-13 levels in (P50.003; P50.002; P5 0.03 respectively), in addition to increasing serum total IgE (P50.03). CONCLUSIONS: This work suggests that topical application of peanut oil may play a role in the etiology of peanut allergy. 1
794
Predicting Baked Milk and Baked Egg Challenge Outcomes with Serum Specific IgE Levels
Samantha M. Knox, MD, and Alton Lee Melton, MD; Cleveland Clinic Foundation, Cleveland, OH. RATIONALE: Serum specific IgE levels can be used to predict the likelihood of reacting on food challenge. Specific IgE parameters for predicting a positive challenge to baked egg and baked milk have not yet been established. We aimed to identify these sIgE parameters. METHODS: We retrospectively reviewed 857 charts of pediatric patients who underwent food challenges at a tertiary care center from January 2013 to May 2017. Demographics and clinical information including age, foods challenged, egg white and cow’s milk sIgE levels, and challenge outcomes were collected and evaluated using ROC analysis. RESULTS: There were 158 baked challenges: 109 baked egg and 49 baked milk in patients aged 11 months to 15 years old. Of the 109 baked egg challenges, 32% failed (35/109), where sIgE ranged from 0.53 to >100 kU/L (median 6.31 kU/L). For baked egg, sIgE of 4.46 kU/L demonstrated a 50% PPV for failed challenge (AUC 0.65, sensitivity 57%, specificity 73%). Of the 49 baked milk challenges, 20% failed (10/49), where sIgE ranged from 2.16 to 39 kU/L (median 18.2 kU/L). For baked milk, sIgE of 15.60 kU/L demonstrated a 43% PPV for failed challenge (AUC 0.71, sensitivity 60%, specificity 80%). CONCLUSIONS: In our study, baked egg and baked milk challenges had higher rates of failure. We identified egg sIgE level of 4.46 kU/L and milk sIgE level of 15.6 kU/L with positive predictive values of 50% and 43%, respectively, for failed baked challenge. This information may aid clinicians in counseling parents regarding appropriate timing of baked challenges.
MONDAY
795
Supervised epinephrine autoinjector administration in a cohort of children with anaphylaxis during oral food challenges (OFCs)
Lianne Soller, PhD1, Timothy Teoh, MD2, Ingrid Baerg, RN, BSN2, Tracy Gonzalez, RN, BSN2, Tiffany Wong, MD, FRCPC2, Kyla J. Hildebrand, MD, FRCPC, MScCH (HPTE)2, and Edmond S. Chan, MD, FRCPC2; 1Division of Allergy and Immunology, Department of Pediatrics, University of British Columbia, BC Children’s Hospital, Vancouver, BC, Canada, 2BC Children’s Hospital, Vancouver, BC, Canada. RATIONALE: An epinephrine autoinjector (e.g. EpiPenÒ, Auvi-QÒ) is the treatment of choice for anaphylaxis in the community. However,
J ALLERGY CLIN IMMUNOL FEBRUARY 2018
studies show it’s often not administered, due to factors including lack of confidence and fear. We previously reported improved confidence after medical supervision of parent/child autoinjector administration during OFCs. We sought to confirm those findings in a larger cohort of children. METHODS: Parents of children undergoing OFC at BC Children’s Hospital filled out a pre-challenge questionnaire on 1) confidence in recognizing anaphylaxis, 2) confidence with autoinjector administration, 3) knowledge of anaphylaxis/autoinjector use, and 4) skill in autoinjector use. Confidence was measured on a 5-point scale (15Not very confident to 55Very confident). Children experiencing anaphylaxis had parent/self autoinjector administration under medical supervision, and confidence was re-assessed post-challenge. RESULTS: Among 308 OFCs performed in 287 children, 50 had anaphylaxis requiring an autoinjector (16.2%). Twenty-one were OFCs to peanut (42%). There was a significant increase in all four confidence domains from pre- to post- challenge (p50.02 for domain 1; p
