Efficacy and safety of oral immunotherapy for peanut allergy: a pilot study in Singaporean children

BACKGROUND: Peanut allergy is an increasing problem in Singapore and strict avoidance is difficult as peanut is ubiquitous in Asian cuisine. OBJECTIVE: We aimed to assess the efficacy and safety of peanut oral immunotherapy (OIT) in children with obvious peanut allergy in Singapore. METHODS: This was an open-label study of peanut OIT in children living in Singapore, with 2 weekly dose escalation until final maintenance dose of 3,000 mg of peanut protein and a maintenance phase of 12 months. An oral food challenge was performed at 6 months to assess for desensitisation and at 4 weeks after discontinuation of OIT having completed 12 months of maintenance therapy to assess for possible sustained unresponsiveness. The adverse events were monitored using the symptom diaries. RESULTS: Nine subjects were started on OIT, with 7 managing to complete maintenance phase of therapy. Of these 7, all were able to tolerate at least 3,000 mg of peanut protein by 6 months of maintenance therapy, showing that the OIT was effective. Of these 7, 3 patients complied with the 4-week abstinence period after completion of OIT before another peanut challenge; 2 of the 3 subjects showed a significant decrease from the initial ability to tolerate 3,000 mg of peanut protein. Side effects were mainly gastrointestinal in nature and were more common during the updosing phase than the maintenance phase. No episodes of anaphylaxis were observed in this study. CONCLUSION: Peanut OIT seemed to be effective and safe in our cohort of Singaporean children.

A review of oral food challenges in children presenting to a single tertiary centre with perceived or true food allergies

<p><b>INTRODUCTION</b>The prevalence of perceived food allergies exceeds that of true food allergies. Unnecessary food avoidance may increase parental and patient anxiety, reduce quality of life and increase the risk of nutritional deficiency. An oral food challenge (OFC) can provide an objective measure regarding the presence or absence of food allergies in a child. This study reviews the indications for and outcomes of OFCs performed on children.</p><p><b>METHODS</b>A retrospective review was performed on all children who underwent OFCs at the Allergy Unit of the National University Hospital, Singapore, over a three-year period.</p><p><b>RESULTS</b>A total of 197 OFCs were performed among 58 patients (34 male, 24 female). Most of the tests were for allergies to tree nuts (n = 107). Among the OFCs, 43.1% were for foods that were avoided and never eaten due to perceived food allergies, 25.9% were for foods that had previously resulted in positive skin prick tests (SPTs) and/or immunoassay results, 16.2% were for foods thought to worsen eczema and 14.7% were for foods thought to have caused a previous reaction. Of all the OFCs, 5% were positive, although adverse reactions were mostly cutaneous. Challenge-positive patients had either positive SPTs (wheal > 3 mm) or raised serum immunoglobulin E levels to specific foods that they reacted to during the challenges. No episodes of anaphylaxis were reported after the challenge. Most of the patients were able to safely introduce the avoided foods into their diets.</p><p><b>CONCLUSION</b>OFCs provide an objective assessment for suspected food allergies.</p>