Becky Chamberlain holding her son

By Becky Chamberlain

My son, Harvey, started Oral Immunotherapy treatment for peanut allergy when he was just a year and a half old. After a positive start, we had to stop the programme because he developed a side-effect called EoE, but we’re still holding out hope for future treatment.

Embarking on OIT

After tolerating peanut for 8 months, Harvey suddenly developed hives on three occasions in just one week when eating peanut, he was 15 months old.

After discussing with his allergist, we were advised we could start OIT at home with Bamba peanut puffs*. I was told to start with 1/16th of a puff, doubling every two weeks if there are no symptoms. I felt fairly confident going into the desensitisation given he had been tolerating large amounts of peanut previously in his diet. Cutting a puff into 16 was the hardest part!

A positive start

My husband was present for the first dose and for every time we up-dosed, in case there was a reaction. Harvey loved peanut prior to starting and we had no problem getting him to eat his doses. We would give it to him first thing in the morning, just before breakfast, so we knew he would be able to eat the whole amount. We would crush it up and mix with a little milk to make a paste and spoon feed him to prevent his skin from coming into contact with it.

We reached 8 puffs with no issues and then progressed to 16 puffs. However, at this point Harvey developed a very minor rash around his mouth – the following day I tried 12 puffs and he tolerated this well. After discussion with his allergist he advised us to remain at 12 puffs a day for a while before up-dosing again.

managing oit for two foods

During this time, when Harvey was 18 months old, he had a cashew nut challenge in hospital. He passed with no issues and so we gave cashew nut butter at home 48 hours later as advised. Unfortunately, Harvey developed a facial rash, and after discussion with his allergist we were happy to start cashew desensitisation at home. We started with 1/64th tsp and doubled every 2 weeks if there were no symptoms.

As Harvey had comfortably eaten a much larger amount at the food challenge I was pretty confident he would be fine with such a tiny amount. Again, my husband was present with the first dose and every subsequent up dose. I would measure it out and spoon feed it to Harvey. Harvey never refused a dose and was always happy to eat it – sometimes asking for more! We reached ¼ tsp with no issues.

We always made sure that there were two hours between his peanut in the morning and cashew later in the day, in case symptoms were to happen and we had a better idea of which one caused it. We also did the up-dosing on different days, so we could make sure we could identify the cause if there was a reaction. We would only up-dose at home and delay if we were away or going to be out all day.

Anxiety during OIT

During Harvey’s OIT I did have allergy anxiety. Harvey was home with me 100% of the time. I was entirely responsible for measuring out, giving the dose and checking for symptoms. When Harvey was 10 months old he had an anaphylactic reaction to something we were unable to identify (likely cross-contamination whilst we were living with grandparents). It was scary how quickly it happened and how unwell he could get from something which is so benign to most people.

Up-dose days would often result in a poor night’s sleep prior and anxiety before, during and after the dosing, but the following two weeks of the same dose were much easier. In front of Harvey we were confident and comfortable, and he never complained or refused a dose.

bumps in the road

During the process we had very few hurdles. There was a couple of times Bamba was out of stock at our usual stockists, so I ended up bulk ordering it online to make sure we never ran low again.

Harvey had one episode of fever and cold symptoms but there was only one day when he could not manage the dose, so we did not have to change the schedule.

Something was wrong

When Harvey had been doing peanut OIT for about 6 months and cashew OIT for four months I noticed he started coughing at mealtimes. With hindsight I think he had probably been on-and-off coughing during mealtimes for four weeks or so. I mentioned it to my husband but he had not noticed, so we continued to monitor him. Over the next 3-4 weeks his appetite reduced, he lost weight, he slept a lot and started refusing to walk or climb stairs. Then he had two episodes of vomiting during mealtimes over a weekend. This panicked me – I knew something was very wrong.

I got an appointment at the GP straight away and she referred us to A&E. I had also contacted his dietitian at the same hospital, given his lack of appetite and now vomiting, and had been given an emergency allergist appointment later in the week. A&E were great but had no clue about allergy and OIT. They did a chest X-ray which showed bilateral chest infiltrations and their primary differential was a neurological cause of the coughing and vomiting with eating. They arranged an urgent follow-up that week with general paediatrics.

EoE diagnosis

By the time we saw the allergist Harvey was rapidly losing weight and becoming very unwell. As soon as we walked in the room, she said she thinks he has developed Eosinophilic Oesophagitis (EoE) from the desensitisation. I had never heard of this before, but she explained it is a known, but rare, complication of OIT. It can only be diagnosed by endoscopy with biopsies of his oesophagus, so we were admitted. The gastroenterologist confirmed EoE on visual inspection during the scope and the biopsies later were positive.

We were advised to stop both OIT treatments to see if he recovered. He required nutritional support with Fortini for a few weeks to prevent further weight loss and he had to have soft food that would more easily pass down his oesophagus to prevent impaction.

After a few weeks Harvey turned a corner. His appetite returned, he slowly started gaining weight, he had more energy and was more interactive. Now, 6 months later, he is a different child – he is more confident with eating and trying new foods, he has much better oral-motor skills, he is finally talking, gaining centiles (not just weight) and has endless energy. Some of this will, no doubt, be normal development but with hindsight he had become so quiet, so still and had withdrawn from food.

For us, OIT did not work

For us OIT did not work. But if I was to go back in time, knowing that EoE is a potential risk, I would still try it again.

I knew OIT was not a ‘cure’. That it was a life-long commitment. But reducing the chance of anaphylaxis was my aim. I was more confident taking him out, dining at restaurants, playing in playgrounds, going on holiday whilst he was undergoing his OIT, because I knew he could tolerate a fair amount of some of his allergens. But interestingly that confidence has remained despite being off treatment for 6 months. Maybe that is because he is older and seems less fragile, or because I have more ‘allergy parent’ experience. Either way, I have less anxiety because we are no longer giving him his allergens.

Holding out hope

I am continuing to explore further OIT options in the future. We’re considering whether we start either peanut or cashew again, to see if we can do OIT for one allergen at a time without developing EoE, or whether to do OIT for one of his other allergens. I want to do what I can to prevent anaphylaxis and I know that the younger he is, the easier and more likely OIT is to succeed.

OIT is not for everyone. There is no right or wrong decision. It is time consuming, expensive (especially if doing privately), restrictive, anxiety-inducing and you must be prepared to experience adverse events. It is also not a cure, and the aim is only to reduce the risk of anaphylaxis, not to be able to freely eat the allergen.

I am holding out hope that further research, especially in biologics, may result in the same outcome without having to eat a whole host of allergens every day and work for allergens that may also cause EoE and cannot be tolerated orally.

*OIT should only be carried out under clinical guidance. 

Please note, Becky’s story is written in her own words and details her personal experience and opinions. The information above has not been signed-off or reviewed by an allergy clinician.

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