Daijiworld Media Network - New York
New York, Oct 3: An observational cohort study has found that an ultra-low-dose induction approach may help children with severe peanut or walnut allergies who were previously unable to begin conventional oral immunotherapy (OIT).
Researchers analysed data collected between 2021 and 2024 from 21 children aged over three years with physician-diagnosed severe peanut or walnut allergy.
The participants had either a history of Grade 2 or higher allergic reactions, including anaphylaxis, or reactions to trace amounts of the allergen, indicating an extremely low threshold that prevented them from starting or progressing with conventional OIT. All participants also had either a positive skin-prick test or elevated allergen-specific immunoglobulin E (IgE) levels.
The children were divided into peanut-allergy and walnut-allergy groups. Both groups underwent an ultra-low-dose induction protocol, with the starting dose individually determined using serial five-fold dilutions of allergen extract.
Participants ingested their selected extract dose twice daily for one month. During monthly clinic visits, the dose was gradually increased by increasing the number of drops and moving to more concentrated extract dilutions, provided the treatment was tolerated.
All participants with peanut allergy and 90.9% of those with walnut allergy successfully progressed to conventional OIT and were able to tolerate milligram-level doses of allergen powder. The median time required to transition to conventional OIT was 16 months for peanut allergy and eight months for walnut allergy.
Most participants were also able to tolerate higher doses during allergen-drop challenges after treatment. Adverse reactions during home-based drop maintenance were rare, occurring in 0.02% of peanut doses and 0.09% of walnut doses. The reactions were mostly mild to moderate, and no participant required adrenaline at any stage.
The study also found that 30% of participants with peanut allergy and 27.3% of those with walnut allergy were able to consume commercially available products containing the respective allergens.
Researchers suggested that the potential benefits of the approach could extend beyond increasing the amount of allergen required to trigger a reaction. The treatment may also help reduce anxiety associated with accidental allergen exposure in everyday life.
The researchers concluded that an ultra-low-dose induction phase could help children with severe peanut or walnut allergies progress to conventional OIT and tolerate milligram-level amounts of allergen protein.
However, they noted that the study's lack of a randomised comparison group and the use of non-standardised allergen extracts were limitations. Further research is therefore needed to confirm the findings and establish the effectiveness and safety of the approach.