Peanut allergy study finds babies should be retested. Here's what parents should know.

It's one of the most common hardships for parents with young kids — policing what their children eat when they are diagnosed with a peanut allergy. 

About one in 50 kids in the United States has a peanut allergy. But a new study from Australia shows parents should consider having their kids retested.

More than one-third of babies thought to have a peanut allergy could safely have the diagnosis removed, according to research from the Murdoch Children's Research Institute and the National Allergy Centre of Excellence, published this week in The Journal of Allergy and Clinical Immunology.  

Infants in the study had recently had a reaction to peanuts and then tested positive for a peanut allergy. However, 34.8% of those infants who tested positive were then found not to have an allergic reaction when given slowly increasing doses of peanuts under strict medical supervision, according to the study.

Oral food challenges aren't being used enough, according to those who conducted the study, as most parents rely on testing alone.

"Oral food challenges are not currently used routinely for every infant with suspected peanut allergy," National Allergy Centre of Excellence Director Kirsten Perrett said in a statement. "But our results show that clinical history and allergy testing alone were not enough to accurately diagnose peanut allergy in many cases. A supervised oral food challenge should be routinely considered to confirm the diagnosis before an infant starts oral immunotherapy."

Those who did not have an adverse reaction during the oral food challenge were considered peanut tolerant and had their allergy label removed, according to the study.

But parents should never attempt doing a similar challenge on their own, experts warn.

"If you have an infant that was diagnosed with a peanut allergy, it may make sense to have a conversation with your allergist about ... an oral food challenge," CBS News medical contributor and immunologist Dr. Tania Elliott told "CBS Mornings." "This is not something to try at home — 12% of those babies had anaphylaxis. OK, so this needs to happen in a monitored setting in the doctor's office, where they're given small amounts of peanut to determine if they're still allergic."

"And all children should be retested, even if they have allergies, every year to determine whether or not they still have the allergy," Elliott added.