Oral Immunotherapy (OIT) in our London Allergy Centre of Excellence.
Background
Oral Immunotherapy to food was first described in 1908 in The Lancet - a case of egg poisoning’ - by a physician practising in Harley Street (pre NHS). This report (open access on the link above) is highly informative. It reflects the process of OIT rather well, where even very allergic patients can enjoy a rise in the threshold of the allergen to which they are allergic.
OIT to foods has enjoyed a massive leap forward thanks to the rigorous, extensive international studies (Palisade & Artemis) that underpin the licensing of a peanut OIT product. Thanks to these studies, we now understand the best regimens and products for successful OIT and the likely associated risks and side effect profiles.
Oral Immunotherapy: A Treatment, Not a Cure, for Food Allergies
Oral Immunotherapy (OIT) represents a significant advancement in the management of food allergies, offering a proactive treatment approach for many patients. However, it is crucial to understand that OIT is not a cure for food allergies. Instead, it is a medical treatment aimed at increasing an individual's tolerance to a specific food allergen, thereby reducing the risk of severe reactions to accidental exposure.
The primary goal of OIT is to achieve a state of desensitisation. This is a temporary state where a person can consume a certain amount of their food allergen without triggering an allergic reaction, as long as they continue to consume a regular maintenance dose. If the person stops their daily dose, their allergy is likely to return. The main benefit of desensitisation is to provide a safety net against accidental ingestion of the allergen, which can significantly improve the quality of life for both patients and their families.
A more profound and less common outcome of OIT is sustained unresponsiveness, which is sometimes referred to as remission. In this state, an individual can stop taking their daily maintenance dose for a period of weeks or even months and still be able to consume the allergen without a reaction. While this is a more durable form of tolerance, it is not achieved by all patients and is still not considered a permanent cure. Even those who achieve sustained unresponsiveness are typically advised to continue carrying an epinephrine auto-injector. We now offer OIT to a wide variety of foods in our Allergy Centre of Excellence.
Currently, we offer OIT to the following allergens; more are being added each month.
Pea OIT
Please be aware of the following principles when considering an OIT program, as OIT is not for everyone and a shared-decision making process is always required:
OIT is not curative; i.e., for most allergens, ongoing therapy is required to maintain tolerance.
OIT seeks to raise the threshold at which a reaction would occur, aiming to render your child ‘bite proof’, i.e. protected from accidental everyday exposures.
OIT is allergen-specific and protects only against the allergen that is eaten (except cashew and walnut, where protection may also be enjoyed for pistachio and pecan nuts, respectively).
Based on the most common experiences of patients undergoing Oral Immunotherapy (OIT), the primary side effects are typically mild and may include:
Oral symptoms: Itching, tingling, or a metallic taste in the mouth.
Skin reactions: Hives, rash, or flushing.
Gastrointestinal issues: Abdominal pain, cramping, nausea, or vomiting.
Nasal or respiratory symptoms: Sneezing, runny nose, or a tight feeling in the throat.
While less common, more severe allergic reactions, including anaphylaxis, can occur, which is why OIT is always conducted under strict medical supervision.common and usually affect the GI system
More severe allergic side effects can occur, sometimes unpredictably, i.e. after months of tolerance. This can arise due to co-factors such as exercise, infections, and medication use.
Emergency medication will, therefore, always be required on your person while undergoing OIT.
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Typically, the process of starting OIT in a private practice involves an initial consultation to assess your child's suitability for the treatment. This will likely include a detailed medical history and may require recent skin prick or blood tests. If OIT is deemed appropriate, the treatment will begin with a very small, controlled dose of the allergen administered in one of our ACE clinics. This is followed by a structured programme of daily doses at home, with regular visits to the clinic to increase the amount of the allergen gradually. The clinical teams provide close support and guidance throughout the process
Please feel free to discuss advances in the field and the potential for OIT for your child when consulting with Prof du Toit.
Prof Du Toit and Dr Foong have been investigators on many of these trials and are actively involved in research testing other treatment modalities, e.g. Viaskin trials.
