Instead of keeping peanuts away from babies with high risk of an allergy, the new advice in the US is for parents to feed small amounts to children during infancy.
Four-year-old twins Audrey and Isa share everything - that is, except Isa's severe peanut allergy. When Isa was diagnosed as a baby, her mother Chia Kuo was given traditional guidance.
"[I was told] no ingestion at all of peanuts and no contact either, because she had a contact allergy where if she so much as touched peanuts she would break out into hives everywhere," Ms Kuo said.
But when Isa's brother Ander was born last year at high-risk for peanut allergy, the plan was reversed; Ms Kuo was told to feed him diluted peanut butter on a regular basis, starting at four months, to avoid developing an allergy.
"He's been able to have it three or four times a week at home with no adverse reactions, so it's a big sigh of relief for all of us," she said.
Dr Hugh Sampson of Mt Sinai Hospital helped write the new guidelines.
"Now we're saying not only is it okay, we're saying 'go do it'," he said. "In these high-risk children we need to get peanut into their diet early to try and prevent peanut allergy."
The guidelines categorise high-risk babies as those with severe eczema, egg allergy, or both. Introducing peanut protein is now recommended as early as four months old.
This regimen lowers the odds of developing peanut allergy by at least 70 percent, leading to the new guidelines.
"I wish something like this would cure peanut allergy but, you know, it's unlikely - [but] I think we can significantly reduce the amount of peanut allergy," Dr Sampson said.