Oral immunotherapy for peanut allergy can successfully desensitise patients to high doses of peanut protein, but the protection rapidly declines once treatment stops, a US study has found.

The findings are consistent with a recent systematic review and meta-analysis of peanut allergy oral immunotherapy trials, which found the experimental treatment increased the risk of life-threatening anaphylactic reactions without improving quality of life.

In the Stanford University-run phase two study, 120 patients with peanut allergy aged 7-55 (median age 11) were randomly assigned to placebo or high-dose peanut protein of 4000mg.

At the two-year mark, those in the high-dose group were either discontinued from treatment or reduced to 300mg peanut protein daily for an additional year.