Novel treatment for food allergy
A: In recent years, extensive studies have been undertaken to explore a variety of novel treatments for food allergies. Among all types of novel treatments, oral immunotherapy (OIT) has been evaluated to the greatest extent on its efficacy and safety. Other forms of immunotherapy for food allergy are also being investigated, such as epicutaneous immunotherapy (EPIT) and biologicals, which may offer a more convenient and potentially safer alternative to OIT in the future.
A: OIT requires patients to regularly expose to one or multiple food allergens via oral ingestion under medical supervision. The goal to gradually and safely increase the individual’s tolerance to the food, with the hope that they will eventually be able to consume a normal-sized portion of the allergenic food without experiencing symptoms.
A: The main treatment outcomes are to induce desensitisation or sustained unresponsiveness – desensitisation refers to an increase in the threshold amount of food to trigger an allergic reaction without experiencing allergic symptom, but it requires regular allergen exposure. In contrast, sustained unresponsiveness, is the state when patients no longer develop reactions upon allergen exposure even though the treatment has been withdrawn for a minimum of 6 to 8 weeks. It is thought to reflect re-programming of the immune system from an allergic to tolerance state.
A: The goal to gradually and safely increase the individual’s tolerance to the food. Patients can then benefit from a better quality of life with lower chance of severe allergic reactions in the events of accidental exposure to allergen or cross-contamination of food. Those who have achieved sustained unresponsiveness can even freely integrate the allergen into their diet, removing the burden of dietary restriction.
A: It consists of three stages in general. The first stage is an initial dose escalation, during which the patient will receive increasing amount of the allergenic food (containing a few micrograms to milligrams of food protein) over hours or days. This will be followed by the build-up phase, where the patient will gradually increase the daily dose of allergen over several months if tolerated. Finally, they will reach the maintenance phase and consume the same amount of treatment food every day (containing up to a few grams of food protein).
A: The optimal duration of OIT for food allergies is not yet known, but most studies suggest that benefits might be maintained if the treatment is continued for at least 12-24 months.
A: Diagnostic tests such as blood specific IgE test, skin prick test and oral food challenge are often done before the commencement of treatment. This is to confirm the diagnosis of an IgE-mediated food allergy in the patients and therefore make sure they are in actual need of the treatment. The tests will often be repeated upon completion of OIT to evaluate the treatment outcomes.
A: OIT has shown promise in treating food allergies, particularly peanut allergy. Multiple clinical trials have shown that OIT can be effective in desensitizing individuals with peanut allergy, with doses of up to 4g of peanuts eventually tolerated, and a reduced risk of severe reactions over time. A smaller number of studies have evaluated OIT for other food allergies, such as cow’s milk and egg, and have also shown benefits for some individuals. Currently, efficacy of OIT for wheat, fish and shrimp allergies are being studied locally.
A: Side effects are common, which include oral and throat itchiness, swelling, hives, tummy pain and vomiting. Sometimes, severe side effects such as trouble breathing and wheezing occur. As such, OIT is typically only performed by allergists or other trained medical professionals in specialized clinical settings and may not be suitable for all individuals with food allergies.
A: Before the start of treatment, the patients, parents and caregivers should be educated on how to recognize allergy symptoms and how to manage them. They should also be informed on the usage of adrenaline autoinjectors and provided an anaphylaxis action plan in order to be prepared for any adverse events induced by the OIT.