Food Oral Immunotherapy

OIT in preschool aged children

Food Oral Immunotherapy (OIT) has emerged as an exciting breakthrough treatment for food allergy, instilling long-term hope for individuals dealing with food allergies. It holds the promise of potentially diminishing allergic reactions and significantly improving their quality of life in the future.

In the past, the sole approach to treating food allergies involved strictly avoiding accidental exposures to the allergenic food, adhering to dietary recommendations, and having an emergency treatment plan along with medication.

However, this new method involves administering small amounts in gradually increasing doses of the food allergens to the allergic individual under medical supervision, resulting in a potential reduction of their allergic symptoms.

Food Oral Immunotherapy (OIT) is also known as Oral Desensitisation (OD), Oral Tolerance Induction (OTI), Food Allergy Desensitisation or Food Desensitisation.

What age should OIT be performed?

Historically, research on food allergies and immunotherapy primarily centred around school-age children, as they were more likely to have persistent allergies. However, recent evidence has emerged indicating that administering immunotherapy to preschool-age children could yield greater success rates.

Specifically, peanut allergen immunotherapy has shown promising results in this regard, leading the way in expanding the age range for effective treatment. This highlights the importance of considering early intervention and broadening the scope of immunotherapy research to encompass younger children with food allergies.

OIT can be considered for children as young as 6 months of age, depending on the specific allergen and the child’s overall health and development. The age at which OIT should be performed depends on various factors and should be determined on a case-by-case basis in consultation with a paediatric allergist with expertise in this field.

Read more about the process in our Food Allergy Desensitisation page, including the desensitisation process for both peanut, and milk and egg.

Peanut OIT studies in young children

Peanut allergy is one of the most common food allergies and can trigger a life-threatening reaction in some. Peanut allergy affects approximately one in 50 children in the UK and is considered the leading cause of food allergy related anaphylaxis, a severe and potentially life-threatening allergic reaction in the country.

Previously, to mitigate the risk of an allergic reaction, those affected were advised to avoid all forms of peanut and peanut-containing foods. However, practical challenges make strict avoidance difficult, leading to accidental reactions occurring in 7-14% of peanut-allergic individuals each year.

There is growing interest in providing oral immunotherapy at an early stage of life, during the maturation of the immune system, as it may potentially yield more effective modifications in a child’s immune response to peanuts compared to later interventions.

In the IMPACT study, researchers gave children with peanut allergy aged 1 to 3 gradually increasing oral exposures to peanut over time to desensitise the individuals to peanuts. After two years of treatment, these children were asked to avoid peanut for 6 months and had another peanut challenge. In children aged 1-2 years of age, 71% of children were still able to tolerate the peanut oral food challenge, indicating that their peanut allergy was in remission. Two previous studies offered evidence supporting the safety and therapeutic benefits of administering peanut oral immunotherapy to very young children.

These findings contribute to the understanding of the potential positive impact of early initiation of peanut immunotherapy in managing peanut allergies.

Find out more about IgE Mediated Food Allergy and Non IgE Allergy in the Conditions section of our website.

How safe is OIT in Preschool Aged Children?

Oral Immunotherapy (OIT) safety can depend on various factors. As mentioned above, one of the serious risks associated with OIT is the potential for anaphylaxis, a severe allergic reaction that can be life-threatening. The risk of anaphylaxis is not equal across all age groups – it is generally found to be significantly lower in preschool-aged children as compared to children of school age or older.

While anaphylaxis is a possible risk, the majority of adverse events with OIT are usually mild and often involve symptoms affecting the skin or gastrointestinal tract. Particularly in younger age groups like toddlers, these symptoms tend to be less severe. They may manifest as skin rashes or gastrointestinal discomfort, among other symptoms.

Certain factors, known as cofactors, can increase the probability of reactions during OIT. These include instances like having a viral infection, not having a snack with the dose, or engaging in exercise. These cofactors can act as triggers and can potentially heighten the risk of an adverse reaction to the treatment.

While Oral Immunotherapy holds promise as an effective treatment for allergies, its safety must be evaluated on an individual basis. It’s essential that anyone considering OIT discuss potential risks and benefits with their healthcare provider.

How Children’s Allergy Doctors can help…

The introduction of Palforzia, a specific treatment for peanut allergy, has proven instrumental in diminishing the severity of reactions to peanut allergy including anaphylaxis, thereby allowing children to engage in activities like family holidays, birthday parties, and enjoying Christmas treats, which were previously challenging or impossible for them.

Palforzia involves monthly doses, allowing a gradual and controlled development of tolerance over time. This groundbreaking treatment has been made available to children and young people in England, making them the first in Europe to benefit from it through an access agreement facilitated by the NHS.

However, for children aged 4 and under, there are alternative options that can be explored which we provide at Children’s Allergy Doctors. These alternative options cater specifically to younger children and aim to facilitate their desensitisation process.

For individuals to be considered appropriate candidates for food oral immunotherapy treatment, it is crucial that both parents and children demonstrate a strong commitment to strictly avoiding exposure to the allergenic food and comply diligently with the prescribed treatment regimen.

This includes adhering to daily dosing requirements and attending regular follow-up visits. The success of food desensitisation relies heavily on the cooperation and dedication of both parents and children in maintaining a safe and controlled environment to minimise the risk of allergic reactions and ensure the effectiveness of the treatment.

If you would like to find out more about Food Oral Immunotherapy (OIT) in preschool aged children, please contact our practice team on 0203 146 7721 or email


Imperial College London – First study of a new immunotherapy treatment for peanut allergy launches

US National Institute of Health – Oral immunotherapy for peanut allergy in young children

NHS England – New treatment to reduce effects of peanut allergy to benefit thousands of children


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