ABOUT
The Process
Important Notice: Just because your child is suitable for desensitisation, does not mean it is the right treatment for them. It is critical that there is a process of shared decision making, discussing the benefits, risks, alternatives and implications of not doing the treatment. This process will be supported by lots of written information to help you make the right decision for your family, which may well be to continue to avoid peanut.
Oral Desensitisation (OD), also known as Oral Tolerance Induction (OTI or OIT) or Food Desensitisation, is a treatment that involves giving very small, but gradually increasing, amounts of the food that the child is allergic to. The intention of OIT is to increase the tolerance to the food so that larger amounts of it can be consumed without causing any symptoms and, as a result, accidental exposures to small amounts of the food should not cause reactions.
This treatment has been most studied for milk, egg and peanut.
In 2020, PALFORZIA became the first licensed food immunotherapy treatment initially in the US and then in Europe. This was the result of large, international studies to show its effectiveness and safety.
Each PALFORZIA dose contains consistent, precise amounts of peanut protein in the form of a peanut flour. The flour will be sprinkled from a capsule, or sachet at higher doses, and mixed with preferred soft foods that can be eaten cold e.g., yogurt (milk or Soy, allergies depending) or applesauce. The PALFORZIA doses are accurately measured which is important when the OIT journey is to start at very low doses e.g. 3mg of peanut protein which equates to 100th of a peanut kernel containing 300mg of peanut protein.
It is important to recognise that this treatment leads to a state of desensitisation (a temporary state, where greater amounts of peanut can be tolerated without symptoms) and not necessarily true ‘tolerance’ (a permanent state where any amount of peanut can be consumed without any risk of reaction). In practice, this means that the regular doses of peanut must be continued regularly in the long term for the treatment effect to remain. If it isn’t, the risk of reaction returns.
It is also important to realise that the treatment is ‘allergen specific’ i.e. the improved tolerance will only be to peanut and not to any other food allergens that your child may be allergic to.
The Palisade and Artemis trials have also demonstrated that the reaction severity that occurs to very high amounts of peanut decreases on therapy, and levels of tolerated peanut (and immune changes that support such changes) improve over time.
What does the treatment actually involve?
Assessment
After completing the ‘Am I suitable?’ questionnaire we will review this and if it looks like PALFORZIA may be suitable, you will be offered an assessment visit to discuss the process and ensure that you fully understand it. The assessment will involve a detailed history and examination focussing on the peanut allergy and may require skin prick or blood tests for peanut allergy if these have not been done for more than 6-12 months. It will also require a detailed asthma assessment and, where appropriate, lung function testing as any child whose asthma or eczema is not extremely well controlled, would not be suitable for starting treatment. If there is any uncertainty around the diagnosis of a peanut allergy, then a food challenge may be required to confirm this. Some families may wish to undergo a food challenge at baseline to assess the threshold and severity of reactivity, so that a comparison can be made over a time on therapy; this is not required as standard.
Consent
If it is felt your child is suitable for the treatment, you will be provided with written information and given plenty of opportunity to ask any questions. When you feel ready, you will be asked to sign a consent form to indicate that you have fully understood the risks involved. Older children will be asked to sign an assent form confirming they are motivated and willing to undergo therapy. If you do not already have them, you will be prescribed adrenaline autoinjectors e.g. Epipen and trained in their use, so that you are well prepared to deal with a more severe allergic reaction.
Initial Dose Escalation
At your child’s first treatment appointment, they will be given a series of tiny but increasing doses of PALFORZIA (from 0.5mg to 6mg of peanut protein) under direct supervision of our specialist nurses. If your child can tolerate at least 3mg, they can continue on to the next step in the treatment pathway. This is the longest visit lasting about 4 hours. If your child reacts to these tiny doses, they may not be suitable to continue the treatment.
Up-dosing
You will return to our centre the next day, so your child can begin the Up-Dosing phase of treatment. We will administer the first dose of PALFORZIA and monitor carefully to make sure your child can keep taking PALFORZIA. As long as this goes well, starting on the next day, you will give your child the same dose of PALFORZIA every day at home, mixed into a small amount of soft food, until it is time to visit us again (about 2 weeks later) to see if your child is ready for the next, higher dose. Up dosing takes about 6 months to complete, with approximately 11 visits in all.
Maintenance
After your child has completed Up-Dosing, they should be showing a decreased sensitivity to peanut allergen. To maintain this treatment effect, they will still need to continue taking PALFORZIA every day. This is called the Maintenance Dose and is around 300mg of peanut protein – approximately equivalent to one very large peanut kernel. Being able to have this without reacting, will confirm that your child is already at a much lower risk of reacting to accidental exposure to peanut (which are usually less peanut than this).
Follow-Up
Once the maintenance dose is being regularly consumed, there is no need for further visits. However, we will still need to have a 6 monthly check up to ensure everything is going well. Research studies show that whilst the maintenance dose must be continued in order to maintain the effect of the treatment, doing so for an extended period of a year or more appears to enhance the effectiveness of the treatment. There will also be a discussion about switching to alternate peanut products and the options include continuing on the PALFORZIA product, or changing to a favoured product containing a similar amount of peanut protein e.g. an M&M sweet, a measured portion of peanut flour or peanut butter. For some patients/families this will be the preferred option. We will discuss a new appointment in order to supervise the first dose of the chosen food and dietary advice will be given on how to continue on such products. It is important to remember that PALFORZIA is not a cure, your child will need to continue carrying an adrenaline device and bespoke emergency plan and avoid peanut.