Oral Immunotherapy for Cow's Milk Allergy: Five Years' Experience from a Single Center in Turkey

Background: Oral immunotherapy for cow's milk allergy is an effective treatment option because of its ability to increase the threshold for clinical reactions. Aims: To present our experience of oral immunotherapy for cow's milk allergy in the pediatric allergy outpatient clinic, and to evaluate the long-term efficacy of oral immunotherapy and risk factors for adverse reactions during oral immunotherapy. Study Design: Single-center retrospective cohort study. Methods: Forty-two patients with Immunoglobulin-E-mediated cow's milk allergy who complied with the oral immunotherapy protocol were evaluated in this study. The treatment consisted of a rapid escalation phase with an oral food challenge step that included milk doses. During the build-up phase, increasing quantities of cow's milk were administered until the patient was able to consume 200 mL of cow's milk daily. Results: The mean age of starting the oral immunotherapy was 40.2±3.2 (range, 36-156) months, and 54.8% (n=23) of the patients were males. The mean duration of the build-up phase was 18.1±5.6 (range, 9-41) weeks, and the mean maintenance phase was 29.1±11.6 (range, 12-63) months. During the oral immunotherapy, 36 adverse reactions (78% mild and 22% moderate) occurred in 16 (38%) patients. There were no differences in the age of starting the oral immunotherapy (p=0.19), cow's milk-specific Immunoglobulin-E levels (p=0.17), and cumulative provocative doses of oral food challenges (p=0.78) between the two groups of patients with and without adverse reactions. The wheal diameters to cow's milk were higher in the group with adverse reactions (p=0.03). There was no difference in the oral immunotherapy onset age between patients with and without a history of anaphylaxis (p=0.38). The patients with a history of anaphylaxis had more adverse reactions (p=0.04) and a higher number of reactions during the oral immunotherapy (p=0.01), and a higher mean duration of the up-dosing phase (p=0.04) compared with patients without anaphylaxis. Conclusion: Oral immunotherapy is a treatment option in patients with cow's milk allergy because of its high efficacy. Adverse reactions occur in about 40% of cases and are mostly mild. It should be administered with caution to patients with a history of anaphylaxis and a higher wheal diameter to cow's milk in the skin prick test.