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Health & Nutrition - Early days

Practice Nutrition Health
Studies reveal that exposure to peanuts at a young age can raise tolerance in at-risk children. By Meredith Jones Russell

Peanut allergy affects one in 50 children in the UK and is one of the most common causes of food-related deaths. Unlike egg or wheat allergies, it is seldom outgrown. Now, however, there are signs that we could be close to finding a treatment for the symptoms of peanut allergy.

The recent ARTEMIS trial by the Evelina London Children’s Hospital has found that oral immunotherapy treatment, which involves repeated exposure to gradually increasing doses of the allergen, could help sufferers to increase their tolerance of peanuts.

In one of the largest peanut allergy trials ever conducted, ARTEMIS found six in ten four- to 12-year-olds who reacted to around 10mg of peanut protein at the start of the trial were able to take a dose of 1,000mg of peanut protein by the end, equivalent to about three kernels.

The dose of peanut protein, known as AR101, was licensed in the USA for use in four- to 17-year-olds in January under the product name Palforzia.

Professor George du Toit, paediatric allergy consultant at Evelina London Children’s Hospital and the study’s chief investigator, says, ‘It’s extremely exciting. We are one or two years away from having access to a licensed, well-studied product for use for the treatment of peanut allergies.

‘Now the remaining obstacles are regulatory, as bodies in Europe and the UK need to review the safety and efficacy data and the financial implications of treatment programmes. But the product is well-studied, and the evidence is there that it works. This is the final step.’

The researchers are currently running a similar study for one- to four-year-olds with peanut allergies. ‘There is a theory that your immune system is more malleable early on in life, so perhaps it is better to start early. Peanut allergy typically presents in the first or occasionally the second year of life, so if you try to treat it earlier, you may stand a better chance,’ explains Professor du Toit. ‘We want to see if it’s safe, if it works, or even if it works better.’

He is quick to warn, however, that exposure is not a cure for peanut allergy, but just allows for an increased tolerance threshold. ‘Children may need to take it for a really long time, possibly for life,’ he adds, ‘but it does protect from “bite accidents”, or accidental exposures. We call it “bite-proofing” – it will protect you from a small amount of exposure.’

EXPOSURE

Without a cure, prevention is key, and current thinking suggests exposure in infancy could help. ‘Only about five to ten years ago we were recommending total avoidance of peanuts,’ Professor du Toit explains. ‘Now, you are actively encouraged to give babies safe forms of peanuts, which is a total about-turn in approach. In Australia, nine in ten infants are eating peanuts in their first year of life, which would have been unheard of a few years ago.’

The LEAP studies, a set of trials investigating how to prevent peanut allergy conducted by the Immune Tolerance Network, found that regular peanut consumption begun in early infancy and continued until age five reduced the rate of peanut allergy in at-risk infants by 80 per cent compared with non-peanut-consumers.

According to Professor du Toit, ‘If you applied that to children in the UK and the USA, it would stand to decrease the number of children developing a peanut allergy every year by more than 100,000, and can be achieved through a simple, healthy intervention, as long as children avoid whole nuts, which they could choke on, and stick to flours or peanut butter or other peanut products.’

Usually a person cannot have an allergic reaction to a substance they have never come across. But children often react to peanuts the first time they try them.

Professor du Toit explains, ‘This implied that it wasn’t eating them that made you allergic. Most children actually first experience peanuts through their skin rather than their mouths, by being kissed or touched by someone who has eaten peanuts. If they are allergic, they get eczema and develop antibodies. Then, the first time they eat peanuts, these antibodies will be lying in wait and the child will have a clinical reaction.

‘So, the question arose as to why we were all avoiding them. Perhaps we should be eating them early. That is known as the “dual-allergen” hypothesis; that if you’re not eating them and they are applied to your skin, it is riskier, whereas if you eat them early there is a high chance you won’t go on to develop an allergy.’

WHAT IS BEST PRACTICE?

Childcare providers in England and Wales are required to comply with the Food Information Regulation by giving information about the allergenic ingredients used in any food they sell or provide, including pre-packed foods.

PACEY provides webinars, information and resources on how to fulfil the requirements of the regulation, but many settings choose to go fully nut-free, whether or not they have children with identified peanut allergies.

Elissa Abrams, assistant professor in the department of paediatrics and child health at the allergy and clinical immunology section of the University of Manitoba, says, ‘Very young children are more prone to share food or share toys that could be contaminated with food, which could lead to accidental ingestion. However, there are no data supporting the necessity for nut-free classrooms or institutions.

‘The only possible place where this could make sense may be for very young children or in settings where there are developmentally disabled children with food allergies, if there is not adequate supervision around eating to deter sharing food, or not adequate handwashing after food contact, or surface washing after food contact.’

She adds, ‘There is a large misperception that restriction begets safety, especially in older children. It is important to understand that the risk of a reaction either by smelling, or touching, nuts is extremely low.’

What is a peanut allergy?

Peanut allergies usually develop in early childhood and only around one in five children outgrow it, usually by the age of five. Allergies happen when the immune system mistakenly treats proteins found in the peanut as a threat and releases a number of chemicals as a result, which cause the symptoms of an allergic reaction.

Symptoms usually occur within minutes of contact, but can appear up to one hour later. The majority of reactions are mild symptoms and include: