Oral Immunotherapy in a Pediatric Clinic Effective for Multiple Allergies

A similar oral immunotherapy (OIT) approach that is used to induce tolerance to peanuts can be used for nonpeanut foods, and OIT can be undertaken for multiple foods simultaneously, according to study results published in Annals of Allergy, Asthma and Immunology. Furthermore, high baseline test results for allergens are not considered a contradiction for OIT.

OIT has been shown to be effective for inducing tolerance to milk, egg, and peanuts, but using this method to treat allergies to other foods, and in particular, ≥1 food allergy simultaneously, has not been studied thoroughly. Electronic medical record (EMR) review was used to identify 45 patients undergoing OIT for multiple foods who were between the ages of 1.5 and 18 years at the senior author’s pediatric allergy clinic. Patients who had successfully completed OIT, who had ceased OIT, or who were on daily maintenance dosing were included for analysis. Extracted EMR data included baseline allergy test results, other allergic conditions, food allergy history, OIT visits, oral food challenge (OFC) results, and documented between-visit communications with families. Data on methods and outcomes were also summarized and included for analysis to determine correlation with food allergen skin prick tests (SPT) at baseline and specific immunoglobulin E (sIgE) results.

The 45 patients included for analysis undertook OIT for up to 12 food allergies, although most patients (76%) were treated for ≤4 foods. OIT most often included allergies to tree nuts, peanuts, and seeds. At the time of analysis, 35 of the patients were continuing on daily maintenance dosing, 4 were on 3 times weekly maintenance dosing, and 6 had ceased OIT. Among the patients who quit, one did so due to persistent oral allergy symptoms, another due to scheduling problems, 2 patients due to anxiety and food aversion, and 2 patients due to reactions to dosing (a single generalized urticarial reaction for one and recurrent abdominal pain for the other).

During the updosing phase, or the first 3 months of maintenance, 22 (49%) of patients experienced reactions during home dosing or clinic visits, and no patients reported experiencing reactions after the initial 3 months of daily maintenance. Furthermore, 51% (n=23) of patients experienced no reactions throughout the OIT process, 22% (n=10) experienced 1 reaction, and 27% (n=12) experienced ≥2 reactions. Of these reactions, 91% were mild and 9% were moderate, and most were resolved with H1- or H2-antihistamines (3 reactions required injected epinephrine, and 1 required albuterol). No severe reactions were reported. During a similar 18-month time period, 4 emergency department visits (for moderate food allergy reactions) were reported in the 45 patients who received OIT compared with 7 visits for the 44 patients on the clinic’s waitlist.

Data on repeat SPT and sIgE levels after 6 and 12 months of maintenance were available for a subset of the patients. For some of the foods, correlations were found between baseline test results and lowest dose to cause a reaction, threshold for OFC reactions, need for antihistamines, and time to reach maintenance. High baseline allergy test results do not contraindicate OIT participation, although these patients may be more reactive to dosing and may take more time to reach the maintenance dosing phase compared with patients with lower baseline tests.

Because the data for this study were taken from a clinical practice without the rigorous standardization of a research trial and without a control group or blinding, these findings cannot be directly compared with published OIT randomized controlled trials. Nonetheless, investigators concluded, “our clinical experience with multiple food OIT indicates that it is reasonably safe and effective. Reactions were mostly mild, and 87% of patients were successful in reaching a maintenance dose that increases their threshold for food allergy reactions.”

Reference

Eapen AA, Lavery WJ, Siddiqui JS, Lierl MB. Oral immunotherapy for multiple foods in a pediatric allergy clinic setting [published September 5, 2019]. Ann Allergy Asthma Immunol. doi:10.1016/j.anai.2019.08.463