A peer-reviewed Australian study published this week found that about 35% of infants diagnosed with peanut allergy no longer reacted to the food during supervised follow-up testing, meaning the share of children with a lasting allergy is smaller than previously assumed.
The findings, reported by sadanews.ps, come from a trial involving 778 Australian infants around 13 months old who had been diagnosed as allergic after a reaction at home followed by a skin or blood test, usually between 7 and 10 months of age. Every child then underwent an oral food challenge — a procedure in which increasing doses of peanut butter were given every 15 minutes, starting at 1/64 of a teaspoon and doubling until a full teaspoon after 90 minutes. Of the 778, 271 children showed no reaction at all and were reclassified as not allergic. The result suggests that early diagnoses based on a single home reaction plus a positive test may overstate how many children will remain allergic, and it could change how peanut allergies are diagnosed and managed in infancy.
Medical testing confirms temporary peanut allergy diagnoses
- More than one in three babies labeled peanut-allergic in this study passed a supervised peanut-eating test, so the diagnosis was not permanent.
- These challenge tests must happen in a medical setting with experienced specialists — about 12% of the infants had a severe allergic reaction during testing, and medical staff prevented any lasting harm.
Why 35% of “allergic” infants passed the peanut challenge
The gap between the initial diagnosis and the challenge outcome reflects how early allergy testing works. Skin prick and blood tests detect sensitization — the immune system’s production of IgE antibodies against peanut proteins — but sensitization alone does not prove a clinical allergy. A child can test positive yet tolerate the food. The oral food challenge remains the gold standard for confirming whether a true allergy exists, because it measures the actual clinical response rather than a laboratory marker.
Tim Pritchard, a pediatric allergy and immunology specialist at the Murdoch Children’s Research Institute in Melbourne, told the Washington Post that the researchers did not expect such a high pass rate. He urged parents who believe their children have a permanent allergy to reconsider carefully, arguing that supervised food challenges should play a larger role in allergy assessment. He stressed that these tests belong in a controlled medical environment with experienced specialists, not at home.
The mechanism behind the recoveries is thought to involve early, regular exposure to peanut protein, which appears to train the developing immune system to stop treating peanuts as a threat. Prior research indicates that 10 to 20% of allergic children outgrow their allergy before age 4 or 5.
How this fits the shift toward early peanut introduction
The new data extend a trend that began in 2015, when a study in the New England Journal of Medicine showed that early peanut exposure does not increase allergy risk. In 2017, the U.S. National Institutes of Health updated its guidelines to recommend testing peanuts in infants. By 2025, peanut allergy cases in the United States had fallen 43%, according to a study published in the journal Pediatrics.
Key numbers from the study and related research
| Measure | Figure | Source context |
|---|---|---|
| Infants in the Australian follow-up study | 778 (age ~13 months) | Peer-reviewed study published November 4 |
| Children who passed the oral food challenge | 271 (~35%) | Reclassified as not peanut-allergic |
| Infants who experienced anaphylaxis during testing | ~12% | No long-term harm; medical staff present |
| Children previously expected to outgrow allergy by ages 4–5 | 10–20% | Prior research cited in the report |
| Decline in U.S. peanut allergy cases by 2025 | 43% | Study in Pediatrics, following 2017 NIH guidance |
What this means for healthcare systems and costs
Pritchard is currently examining whether performing food challenges at the initial diagnosis could save money over the long term, since children who pass would no longer need regular clinic follow-ups. For families, the practical change is significant: children who pass a supervised challenge are advised to keep peanuts in their diet without specific quantity limits, rather than avoiding them for years.
On funding and transparency: the study was peer-reviewed and published on November 4, but the available reporting does not specify the funding sources behind the trial, which is worth noting when weighing how broadly to generalize the results.
Identifying risks before supervised food challenges
- Oral food challenges are contraindicated at home. They should only be performed in a controlled medical setting with experienced allergy specialists and emergency equipment, because roughly 12% of tested infants in this study experienced anaphylaxis — a potentially life-threatening systemic allergic reaction.
- Children with a history of severe anaphylaxis, unstable asthma, or other conditions flagged by an allergist may need individualized assessment before any challenge.
- Seek immediate medical attention for any signs of a severe reaction — difficulty breathing, swelling of the throat or tongue, widespread hives, vomiting, or collapse — and use prescribed epinephrine if available.
- Parents should consult a board-certified allergist before reintroducing peanuts to a child previously diagnosed as allergic; do not attempt reintroduction based on this study alone.
The question still open after this study
What remains unanswered is how many of the 271 children who passed the challenge will stay tolerant over time, and whether challenging infants even earlier — at diagnosis rather than at 13 months — would raise the pass rate further and cut costs. Pritchard’s cost analysis is still underway, and no long-term follow-up data on the newly non-allergic children have yet been published. Until those results arrive, the diagnosis of peanut allergy in infancy should be treated as provisional, not definitive.
References
- Peer-reviewed Australian oral food challenge study of 778 infants, published November 4, 2026 (reported by sadanews.ps)
- New England Journal of Medicine, 2015 — early peanut exposure study
- U.S. National Institutes of Health, 2017 — infant peanut introduction guidelines
- Pediatrics — 2025 study reporting a 43% decline in U.S. peanut allergy cases
- Washington Post — interview with Tim Pritchard, Murdoch Children’s Research Institute
