Nicole Chase, MD, is a board-certified allergist/immunologist at St. Paul Allergy Asthma, Minneapolis VA Health Care System (part-time), and an associate professor of medicine at the University of Minnesota Medical School.

Nicole Chase, MD

The Early-Life Window: Can Food Allergy Be Prevented Before It Begins?

 in early life was the standard advice. However, new research shows this is not always the case.

A growing body of research now suggests that early exposure, rather than avoidance, may reduce the risk of food allergy and promote immune tolerance during a critical developmental period.

The change began with the Learning Early About Peanut Allergy (LEAP) trial, which showed that by 5 years old, 3.2% of the consumption group and 17.2% of the avoidance group had developed a peanut allergy.

 This represented an approximately 80% relative risk reduction in peanut-exposed children.

Follow-up studies demonstrated that this protection persisted even after a period of peanut avoidance, suggesting durable immune tolerance. A study published in October 2025 analyzed data from > 85,000 children across nearly 50 pediatric practices and found a 27% drop in peanut allergies following the 2015 early introduction guidelines (

 <.001) and a 43% drop after the 2017 addendum (

Building on this dietary prevention model, newer research is expanding attention to early-life immune programming. One area of focus is the infant microbiome, which begins forming at birth and may influence downstream immune responses.

Investigators studying cesarean-delivered infants have examined vaginal microbial transfer as a strategy to partially restore maternal microbial exposure.

 In the ACTIVATE trial, vaginal seeding altered early microbiome composition, shifting bacterial profiles toward those seen after vaginal delivery. Infants who received the intervention also showed differences in food sensitization during infancy, suggesting early microbial exposure may influence allergic risk, although long-term outcomes remain under study.

Mechanistic work has linked microbial activity to immune regulation. Certain bifidobacteria produce aromatic lactate metabolites associated with reduced development of food allergen–specific immunoglobulin E, providing a potential biological pathway connecting microbiome composition to tolerance.

Moreover, translational research examining dietary antigens has identified discrete food-derived proteins recognized by intestinal regulatory T cells; these proteins were found in corn, wheat, and soybean.

 These antigen-specific populations emerge around the time of weaning, when infants first encounter solid foods, and early consumption has been associated with tolerance responses.

These data suggest multiple early-life pathways may influence allergy risk. Microbial colonization, bacteria-derived metabolites, and exposure to dietary antigens each appear to contribute to immune training. This suggests that prevention strategies may extend beyond feeding practices alone to broader early immune development.

: Associate professor of Genetics and Genomics and Immunology at the Icahn School of Medicine at Mount Sinai

An allergist/immunologist at St. Paul Allergy & Asthma and associate professor of medicine at the University of Minnesota Medical School

Clemente J. Vaginal Seeding Partially Modifies Infant Microbiome in ACTIVATE, With Jose Clemente, PhD. HCPLive. Published on March 1, 2026. Accessed on April 13, 2026. 

https://www.hcplive.com/view/vaginal-seeding-partially-modifies-infant-microbiome-activate-jose-clemente-phd

Brix-Pedersen S. Early-Life Bifidobacteria Linked to Lower Food Allergy Risk, With Susanne Brix Pedersen. 

Published on February 4, 2026. Accessed on April 13, 2026. 

https://join.hcplive.com/view/early-life-bifidobacteria-linked-lower-food-allergy-risk-susanne-brix-pedersen

Blum, J. Dietary Epitopes Drive Oral Tolerance, With Jamie Blum, PhD. HCPLive. Published on March 26, 2026. Accessed on April 13, 2026. 

https://www.hcplive.com/view/dietary-epitopes-drive-oral-tolerance-jamie-blum-phd

Gabryszewski S, Gupta R, and Hernandez-Trujillo V. Peanut Allergy Rates Plummet 10 Years After AAP Early Introduction Guidelines. 

 Published October 30, 2025. Accessed on April 13, 2026. 

https://www.hcplive.com/view/peanut-allergy-rates-plummet-10-years-aap-early-introduction-guidelines

Videos

Early allergen introduction, microbiome research, and immune programming studies suggest food allergy prevention may begin during infancy.

 The Early-Life Window: Can Food Allergy Be Prevented Before It Begins?

Why FDA Removed the Age Limit for Epinephrine Nasal Spray

 removal of the minimum age requirement for the 1 mg 

 aligns the product with weight-based dosing used across other epinephrine formulations, such as autoinjectors. The updated label, announced by ARS Pharmaceuticals on March 27, 2026, now allows use in any patient weighing ≥ 33 pounds.

“The drug works in patients regardless of the age requirement,” Nicole Chase, MD, an allergist/immunologist at St. Paul Allergy & Asthma and associate professor of medicine at the University of Minnesota Medical School, told 

. “It's really a weight-based drug, and… it's kind of strange that [the age requirement] was there in the first place.”

Chase noted the decision did not rely on dedicated studies in children younger than 4 years old. Instead, regulators reviewed available pharmacokinetic and pharmacodynamic data and applied an approach similar to injectable epinephrine, which has historically been dosed according to weight.

With expanded labeling, Chase emphasized clinician-led education to minimize adverse effects, particularly during initial use. She recommends hands-on training with demonstration devices during clinic visits.

Proper technique, particularly avoiding sniffing during delivery, may improve tolerability. Chase typically recommends observing patients for approximately 1 hour after administration to monitor response and potential reactions.

If symptoms persist, Chase advises administering a second dose in the same nostril, reflecting study findings showing improved response with this approach. She also recommends emergency evaluation if repeat dosing is required.

Insurance coverage and cost remain considerations, though access programs may help reduce out-of-pocket expenses. Chase described a program that uses a third party to get an epinephrine nasal spray. Overall, she said that the epinephrine nasal spray is doing a job in getting into patients’ hands.

“I’m so glad that the FDA has decided to streamline things,” Chase said. “We already struggle as clinicians…with reassuring parents that epi is safe…effective…[and] the number 1 therapy for a severe allergic reaction like anaphylaxis. Anytime the FDA can remove barriers to making people worry that, ‘oh, is this different somehow? Is this not as good?’ I think that always helps our cause as prescribers to really let them focus on if you even think you need it, just go ahead and take it. Removing that age requirement really just allows us to prescribe like we've been prescribing for other epinephrine devices.”

Part 1 of the interview with Chase can be watched

Relevant disclosures for Chase include GENZYME CORPORATION, Regeneron Healthcare Solutions, Incyte Corporation, Novartis Pharmaceuticals, Blueprint Medicines Corporation, Genentech USA, and AstraZeneca Pharmaceuticals.

ARS Pharmaceuticals, Inc. ARS Pharmaceuticals Receives FDA Approval to Remove Age Requirement From neffy® 1 mg (epinephrine nasal spray) Label. GlobeNewswire News Room. Published March 27, 2026. Accessed March 27, 2026. 

https://www.globenewswire.com/news-release/2026/03/27/3263722/0/en/ARS-Pharmaceuticals-Receives-FDA-Approval-to-Remove-Age-Requirement-From-neffy-1-mg-epinephrine-nasal-spray-Label.html

Campbell P. FDA Removes Age Requirement for Epinephrine Nasal Spray, Now Based on Weight Alone. HCPLive. March 27, 2026. Accessed April 9, 2026. 

https://www.hcplive.com/view/fda-removes-age-requirement-for-epinephrine-nasal-spray-now-based-on-weight-alone

Chase discusses how the FDA’s labeling change aligns epinephrine nasal spray (neffy) with other weight-based epinephrine formulations.

Weight-Based Dosing Informs Age Removal for Epinephrine Nasal Spray, With Nicole Chase, MD

 FDA Removes Age Restriction for Epinephrine Nasal Spray, With Nicole Chase, MD

The US Food and Drug Administration (FDA) recently eliminated the minimum age requirement for the 1 mg 

, allowing prescribing decisions to be guided by patient weight rather than age. The updated labeling now permits use in any patient weighing ≥ 33 pounds.

“We’ve been giving epinephrine safely to younger…and really lower-weight children for a long time,” said Nicole Chase, MD, an allergist/immunologist at St. Paul Allergy & Asthma and associate professor of medicine at the University of Minnesota Medical School. “Now [that] neffy can be prescribed for children that are 33 to 66 pounds in the 1 mg strength, it just mirrors what we've been used to doing for epinephrine auto injectors for the 0.15 mg strength.”

ARS Pharmaceuticals announced the FDA’s approval of the labeling update on March 27, 2026. Before the change, epinephrine nasal spray was indicated for pediatric patients aged ≥ 4 years who met weight-based criteria (1 mg for ≥33 lbs to <66 lbs; 2 mg for ≥66 lbs).

The updated label now guides use, temperature, and storage. A patient should avoid sniffing during dosing. Chase explained that inhaling deeply during delivery has been associated with most reported adverse effects.

“I encourage people to just breathe in through their nose, hold the device so that their fingers actually touch the outside nostrils, and then just depress the plunger so that they don't accidentally sniff when they administer it,” she said.

If a patient inadvertently sniffs after nasal administration, the label states to continue the care as normal. A patient does not need a second dose if symptoms improve within 5 minutes.

The updated label provides reassurance for families worried about environmental exposure. The nasal spray can tolerate brief temperature changes, including freezing followed by thawing, and short periods of heat exposure up to 122°F.

“I like to say, if you're comfortable, it's comfortable,” Chase said.

Counseling families on storage remains essential, she added. The label states that the device should be kept in its blister packaging or carrying case and stored at room temperature whenever possible. ARS Pharmaceuticals announced it plans to provide a carrying case with each prescription at no cost beginning this summer; the case is designed to hold 2 devices.

Chase also highlighted the longer shelf life of the nasal spray compared with many injectable epinephrine products, which may reduce the burden of frequent replacement. Intranasal epinephrine can also reduce needle anxiety.

She added that the availability of multiple delivery options allows clinicians to tailor recommendations to individual circumstances. For example, intranasal epinephrine may be particularly helpful for children attending camps, spending time outdoors, or in school settings where storage and usability are concerns.

In clinical practice, Chase has administered intranasal epinephrine during supervised food challenges and observed favorable tolerability among pediatric patients.

The removal of the age restriction may ultimately improve treatment adherence, which remains a significant challenge in anaphylaxis management. Chase emphasized that increasing comfort and accessibility could encourage earlier use of epinephrine during allergic reactions. She stressed that epinephrine remains safe and effective, and delays in administration pose greater risks than unnecessary use.

“If a [child] even think[s] they're having a reaction, I really want them to go ahead and take epinephrine,” Chase said. “I like to say that they can just ask for forgiveness instead of asking for permission. Epi is safe and effective, and it really prevents the bad [food allergy] outcomes.”

Chase explains how the weight-based labeling update for epinephrine nasal spray (neffy) may improve access, adherence, and real-world use in young children.


Nicole Chase, MD

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