FeNO as a Marker of Allergic Reactions to OFC and Response of OMA Treatment in Multiple FA

Inclusion Criteria: * Patients must meet the following criteria for study entry: * Able and willing to provide written informed consent from patient and parent or guardian and to comply with the study protocol. * Age 6 years of age or older at Visit 1 * Documented history of food allergy to one or more of the following foods based on SPT performed at baseline visit: * peanut * milk * egg * tree nuts (Walnut/Pecan, Cashew/Pistachio, Almond, Hazelnut, Brazil nut) Exclusion Criteria: * Patients who meet any of the following criteria will be excluded from study entry: * Diagnosis of asthma requiring maintenance medication, including inhaled steroids, leukotriene modifiers, LABA/ICS, biologics medications (Intermittent asthma \[Step 1\] is allowed and defined according to the 2020 NAEPP guidelines (as 'asthma requiring only prn SABA use) and FEV1 \< 80% of predicted normal. * Diagnosis of nasal polyps, cystic fibrosis or any respiratory condition that will skew normally occurring FeNO levels * FeNO (measured in ppb) is lower than a value expected for the age, height, and gender of the participant or inability to perform respiratory collection maneuver * Systemic steroids, leukotriene modifiers, or nasal steroids for any cause/diagnosis within 4 weeks of baseline * Biologic use, for any diagnosis, within five half-lives of Screening * Antibiotic use, systemic/oral/intramuscular, for any cause/diagnosis within 2 weeks of baseline * Active smoker, cigarette, cigar, vape, recreational, and/or prior 10 pack year history * Participant weight or IgE levels outside of the dosing table for OMA * Known history of anaphylaxis/hypersensitivity to OMA * Any medical condition that is serious or unstable that in the opinion of the PI could confound the study results and/or interfere with subject participation or adherence * Pregnant or breastfeeding, or intending to become pregnant during the study or within 60 days after the last dose of OMA * Women of childbearing potential must have a negative serum pregnancy test result during the screening period