Effect of Omalizumab in the Skin of Food Allergy Patients

This is a phase IV open-label interventional pilot study of 30 patients enrolled at National Jewish Health to examine skin barrier function and response to OFC in patients with FA before and after 4 months of treatment with omalizumab. If enrollment is insufficient at National Jewish, Children's Hospital Colorado or another similarly qualified site will be used as a back-up site. Efficacy assessment will be assessed by the ability of Omalizumab to reduce clinical response to OFC. The safety of omalizumab will be concomitantly recorded. Specifically, we will: 1. Examine TEWL, STS lipidomics, metabolomics, cytokines, and proteomics in 30 patients with a history of IgE-mediated reaction to 1 or more foods assessed by sensitization food extracts using skin prick tests, serum IgE to specific foods and/or relevant component proteins, and an IgE-mediated clinical reaction to a food on OFC. 2. Confirm the diagnosis of IgE-mediated FA in all patients with a positive OFC. 3. Treat all 30 patients with omalizumab for 4 months 4. Repeat OFC after 4 months of omalizumab therapy. 5. To analyze TEWL, STS Lipidomics, metabolomics, proteomics, and cytokines in all 30 patients who were treated with omalizumab and completed the end of study OFC. Sample size will be 30 completed subjects. Enrollment will occur over the course of 16 months, with 2-4 participants enrolling each month. Up to ten healthy control subjects will also be enrolled for skin tape strip analysis and TEWL as a comparator group to the FA group. All participants will have an initial screening visit where their clinical history of having an IgE-mediated reaction to specified food(s) will be elucidated, along with review of relevant skin prick test (SPT), food-specific IgE values, and Total IgE. If these values were not obtained within the last 12 months, SPT, sIgE, and/or Total IgE will be performed at screening. All food-allergic participants will undergo an open Screening OFC to one of their food allergens. For continuation in the study, the participant must experience dose-limiting symptoms consistent with an IgE-mediated reaction, at or before 444mg of food protein cumulatively. If they have a negative OFC, additional screening OFCs may be performed to any eligible food. STS and TEWL measurements will be performed prior to the first dose, as well as before the second and third doses. If/when the participant has dose-limiting symptoms, STS and TEWL will be stopped immediately. All food-allergic participants will receive omalizumab for 4 months. All injections will be administered by a research nurse on the clinical research unit. At the midway point of the study (2 months after the first omalizumab injection), the participant will have STS and TEWL measurements performed. After 4 months of omalizumab administration, an end of study OFC will be performed to the same food that was positive at the screening OFC to assess treatment effect, along with analysis of the STS and TEWL.