Specific Oral Tolerance Induction in Food Allergy in Children: Efficacy and Clinical Patterns of Reaction

Abstract

Staden U, Rolinck-Werninghaus C, Brewe F, Wahn U, Niggemann B, Beyer K. Allergy. 2007;62(11):1261–1269 PURPOSE OF THE STUDY. To evaluate the efficacy of oral tolerance induction as a treatment for cow's milk and egg allergies. STUDY POPULATION. Forty-seven children aged 0.6 to 12.9 years with positive double-blind, placebo-controlled food challenges to milk or hen's egg were included in this German study. Children with severe eczema were excluded. METHODS. Subjects were randomly assigned to specific oral tolerance induction or continued avoidance. Treatment involved home escalation over at least 67 days from a dose of 1 drop of cow's milk to 250 mL or from 5 mg of lyophilized hen egg powder to 3500 mg. Subjects continued home dosing for a median of 21 months total, after which time they underwent a secondary period of avoidance for 2 months followed by a food challenge. RESULTS. At follow-up challenge, 9 (36%) of 25 children in the specific-oral-tolerance-induction group showed permanent tolerance, 3 (12%) of 25 were tolerant with regular intake, 4 (16%) of 25 were partial responders, and 9 (36%) of 25 did not complete the treatment because of adverse effects. In the control group, 7 (35%) of 20 children were tolerant at the study end. Allergen-specific IgE levels decreased in children who developed tolerance both in the control (P < .05) and treatment (P < .001) groups. CONCLUSIONS. Specific oral tolerance induction may be a valid treatment option for patients with persistent food allergy. However, only a minority of patients had evidence of persistent tolerance once treatment was stopped, with some unable to tolerate the therapy and others seeming to be only transiently desensitized. REVIEWER COMMENTS. Allergen-specific immunotherapy with injected extracts has proven too dangerous to be a viable treatment method for food allergy. Sublingual or oral immunotherapy, as described here, is a promising alternative to strict avoidance. Although one third of the patients in this study had to withdraw because of adverse effects, the remaining patients were able to incorporate the allergen into their diet at some level. This treatment modality is highly promising, but it is still experimental, carries the potential for significant risk, and requires close monitoring by experienced physicians. Several studies of oral and sublingual immunotherapy for food allergy are ongoing in the United States and Europe.