Single Tree Nut
Bradatan et al.21 reported the results of 37 children treated with tree nut/peanut-OIT for up to two years, to reach a target daily dose of 4gr of nut/peanut. At 18 months 25 passed an OFC to their respective tree nut. Three peanuts-, two cashew- and one hazelnut-OIT children withdrew early because of allergic side effects. Most of the reactions reported during the maintenance phase were transient and required no treatment.
The NutCRACKER study22 described the results of walnut OIT in 55 walnut allergic children; 49 reached maintenance (4000mg of walnut protein) and were considered desensitized, three increased their ED and were considered partially desensitized, and three did not complete treatment (one due to anaphylactic reactions). At least one adverse reaction was reported by 47 children at the hospital up-dosing, and by 40 at the home-dosing, mostly mild, with respiratory and gastrointestinal symptoms. Epinephrine was administered to 11 children at the hospital and 8 at home. Three had symptoms compatible with oral immunotherapy-induced gastrointestinal-and-eosinophilic responses (OITGER), which subsided with temporary dose reduction. Nine children of the control group began OIT, seven were desensitized and were included in the subsequent analysis. After achieving walnut desensitization at 4000mg the maintenance dose decreased to 1200mg daily. 45 participants followed up for at least six months, 11 reported mild allergic reactions requiring antihistamines, and one required epinephrine. After six months, all successfully consumed a single dose of 4000mg of walnut protein.
The results of a low-dose walnut-OIT in 3 children were recently reported by Sasamoto et al.37. Children received an individualized home starting dose and gradually reached the maintenance dose of 75mg of walnut protein after 3, 4, and 3 months respectively. The overall adverse reaction rate per intake at home dosing was 3.1%, including two anaphylactic reactions. No epinephrine use was required.
Hazelnut-OIT was first described by Morally et al.32in a retrospective study of 100 children. After six months on an individualized up-dosing protocol to a low maintenance dose (half of baseline ED), 34 were desensitized to a cumulative dose of 1635mg hazelnut. Median ED increased by 417mg. The remaining 66 children had at least doubled their baseline ED at six months. Side effects were retrospectively reported by 76 children; 30 reported at least one non-severe reaction. Symptoms suggesting eosinophilic esophagitis (EoE) or serious side effects were not reported.
Sabouraud et al.33 reviewed the medical records of 70 children undergoing hazelnut-OIT, including four children with hazelnut sensitization, but no history of ingestion. At baseline, a low-dose OFC with hazelnut was used to establish an individualized, intermediate, 6-months target dose. The procedure was repeated every 6 months until a final individualized dose was reached. At 1 year, 16 children had reached maintenance, and 36 ingesting >120mg of hazelnut protein. The cumulative reaction dose increased from 13mg to 741mg. 40 children had at least 1 adverse effect at home, of which half were mild, 17 developed hazelnut aversion, and 14 reported recurrent abdominal pain. Severe systemic reactions were reported by two children, one of whom required epinephrine. Among 212 OFCs performed, seven severe systemic reactions were recorded, with four requiring epinephrine. One child developed EoE.
Cashew-OIT was described by Elizur et al.25 in 50 cashew-allergic patients. At a median time of 12 months, 44 reached the target dose of 4000mg cashew protein and were considered fully desensitized, three tolerated 1200mg and considered partially desensitized, and three discontinued. The 44 desensitized participants were instructed to consume daily 1200mg of cashew protein. After 6 months they were all successfully challenged to 4000mg. At the in-hospital build-up 44 participants experienced at least one allergic reaction, mainly mild to moderate, while epinephrine was required in 9 participants. At home dosing, 26 participants reported allergic reactions, mostly mild, and three reported epinephrine administration. One patient developed OITGER symptoms and one developed EoE.