Peanut allergy affects about one per cent of the population in westernized countries, the authors wrote, and previous studies have shown that the prevalence of peanut allergy, which can be fatal, has doubled in the UK and US over the past decade. Due to very limited therapeutic options – peanut avoidance is currently the only way to prevent a reaction, but even tiny amounts can trigger a response – there is a need for alternatives.
Peanut oral immunotherapy (OIT) – in which patients are given tiny amounts of ground peanuts at a gradually increasing dose – has been shown to raise the tolerance threshold for allergic reactions. Many researchers and allergy sufferers have been holding out hope that the therapy could eventually help them avoid reactions due to accidental exposure. However, although there has been some cause for optimism, according to this latest review the results from recent trials have been mixed.
In one recent OIT study, for example, 17 out of 22 patients could not reach a 500mg dose of peanuts, and 18 per cent dropped out due to secondary side effects from the therapy.
The review's authors wrote that the major issue to address is whether accidental ingestion of peanuts resulting in an allergic reaction is more or less likely than being unable to tolerate oral immunotherapy.
“Although everyone involved in patient care and in novel therapeutic research would like a treatment option to offer individuals with food allergy, now is not the right time,” they concluded. “Further studies are needed to address these outstanding issues to determine whether this type of therapy is appropriate for clinical use.”
Peanut allergies are rising in humans, with an estimated 2.5 million people in Europe and the US now vulnerable to the food allergy.
Source: Journal of Allergy and Clinical Immunology
“Peanut oral immunotherapy is not ready for clinical use”
Authors: Ananth Thyagarajan, Pooja Varshney, Stacie Jones, Scott Sicherer, Robert Wood, Brian Vickery, Hugh Sampson, and A. Wesley Burks.