Can we use nuts to cure nut allergies?
Peanut allergy is a common disease in developed countries, affecting approximately one in 50 children in the UK. It is the most common cause of fatal food allergy reaction and is most often diagnosed during in childhood, although it can appear for the first time at any age. Unlike some other food allergies, peanut allergies rarely go away, most children will grow into adults with peanut allergy.
Reactions vary in severity, and include mouth itching, nausea, stomachache and vomiting. Itchy nettle sting-like rashes and swelling also occur. More serious reactions involve wheezing, throat tightness and shortness of breath, requiring hospital treatment.
Currently, the best treatment is peanut avoidance. Patients manage this with varying success; accidental reactions happen frequently and families have to carry emergency medication with them (including injectable adrenaline) in case of a reaction. The fear of accidental exposure through food reduces the quality of life of affected individuals and their families, limiting their social lives.
What we did
Based on the encouraging results of a small pilot study, NIHR researchers undertook a randomised trial of a new treatment: peanut oral immunotherapy. This involved 99 children, aged between seven and 16 years, who had an immediate hypersensitive reaction after eating peanut and a positive reaction to a skin prick test.
The participants started with ingesting a tiny amount of peanut protein and eventually built up to the equivalent of five peanuts a day.
What we found
The results showed that an encouragingly high proportion (80–90%) of allergic children could eat 4–6 peanuts regularly after the treatment and that many (50–60%) could eat the equivalent of up to 10 peanuts at a time.
In addition to the high rate of desensitisation, the increased tolerance for daily ingestion of up to five peanuts for a high proportion of participants is of great significance to patients. This quantity of peanut exceeds levels likely to be found in contaminated foods, therefore removing the fear of accidentally eating peanut and experiencing a severe allergic reaction.
The families involved in the trial commented that oral immunotherapy has transformed their lives, reducing anxiety surrounding accidental peanut exposure and allowing patients and their families and friends more freedom in food choice and social activities. The provision of this treatment to peanut allergy sufferers has the potential to lead to a significant reduction in their use of primary and secondary healthcare resources. For example, fewer visits for primary care support should be required, alongside fewer prescriptions for adrenaline and less training for its administration.
Thomas Baragwanath said:
“The trial has helped me so much and I’m really thankful to the doctors and nurses at Addenbrookes. I know there are a lot worse things than peanuts out there, but it has been a massive problem for me since I was a small child and I’m so thankful I’m getting rid of it. It has really helped me a lot.”