When to Diagnose Asthma in Kids Under 5: GINA 2025

For children under 5 years old, an asthma diagnosis rests entirely on clinical judgment—no spirometry, no objective biomarker, just history, physical examination, and treatment response. The GINA 2025 guidelines formalized that process with 3 required diagnostic criteria: recurrent wheezing episodes, having no likely alternative diagnosis, and a documented treatment response. However, translating guideline language into exam-room decisions remains a challenge, particularly when viral-induced wheezing dominates the picture.

Preschool asthma was on the agenda at the Eastern Allergy Conference (EAC) 2026 this spring in Palm Beach, Florida, where Leonard Bacharier, MD, from Vanderbilt University, tackled the question of how to define and manage the condition in its earliest, hardest-to-pinpoint years.2 HCPLive spoke with Jose Arias Jr., MD, partner at Allergy Asthma Specialists, P.A., and associate professor at the University of Central Florida College of Medicine, to get a practicing allergist's take on navigating those same questions, from first diagnosis through the decision to start a toddler on daily controller therapy.

HCPLive: The GINA 2025 guidelines moved away from the probability language used in 2024 and introduced three required diagnostic criteria for children under 5. From a clinical standpoint, does that feel like a meaningful shift?

Arias: [I'd call] it a slight improvement. We have to remember that in children under 5, asthma is a clinical diagnosis. There’s nothing we can do to prove it. There's no pulmonary function test.

[All] we can do [is] talk to the patients [and] listen to the child. These guidelines at least give some guidelines as far as what to do with children under 5.

HCPLive: How often are you able to meet all 3 GINA criteria before formally diagnosing and treating a preschooler?

Arias: It depends [on the patient]. By the time the patient comes to me, they have already tried short-acting bronchodilators, and there's a history of wheezing. Usually by the second or third visit, I'm able to make a full diagnosis of asthma.

HCPLive: Viral-induced wheezing is extremely common in this age group. What's the line between that and early asthma, and how do you communicate that distinction to families?

Arias: What I tell parents is [that] it's difficult to diagnose asthma in a child under 5 if the wheezing [is] related to upper respiratory infections or an illness. I say we will have a better answer on [the patient] once we’re able to do a full pulmonary function test. Most folks say it’s 5 [years old]; I’ve seen 6- [or] 7-year-olds do it. 5 years old is rare that they’re able to do it.

I used to tell the parents we’re going to treat them like they have asthma. Now, [with GINA 2025], we can actually give them a diagnosis of asthma, but it’s not 100% until we’re able to do the pulmonary function test.

HCPLive: Spirometry is unreliable in children under 5. What tools or clinical markers do you actually lean on when trying to determine whether a wheezing preschooler is on a trajectory for persistent asthma?

Arias: On children [4 to 5 years old], we're able to do peak flows, not a full pulmonary function test or spirometry. We’re doing the peak flow 3 times [before and after treatment]. We give them an albuterol treatment, or short acting bronchodilator, and then we repeat it again.

HCPLive: Evidence suggests ICS may not be disease-modifying in early-life wheezing and that targeting eosinophilic airway inflammation alone isn't sufficient. How does that shape your decision-making around when to start controller therapy in a child this young?

Arias: For me, controller therapy [becomes appropriate when] the patient is still having symptoms [despite] using a short-acting bronchodilator.

HCPLive: GINA 2025 recommends low-dose daily ICS as the primary maintenance approach in preschoolers, delivered via pMDI with a spacer and mouthpiece or face mask. Are most families able to execute that correctly, and what does device education look like at this age?

Arias: We have a system now in my office where we give the parents the nebulizer machine and a mask that they can take home and start using right away. We teach the parents how to use it, and a lot of times, unless a child has behavioral problems, they’re able to sit through the treatment plan and complete the whole treatment without any issues.

HCPLive: Preschool and school-age asthma may share similar symptom presentations but likely have different underlying pathologies. How does that heterogeneity affect treatment decisions when you can't reliably phenotype a 3-year-old?

Arias: We treat based on symptoms and history. There’s guidelines, but there's also what the patient has tried in the past [and] what works.

HCPLive: What's the conversation you have with a parent when you're starting a young child on daily ICS, specifically around concerns about long-term steroid use?

Arias: I tell them that this could be for life. I [provide] an example of myself and my children. I have had asthma all my life. This could be that maybe when they go through puberty, it could go away like it did on some of my patients and some of my family members. So, we have no way of knowing, but at the same time, we need to do this treatment for this patient to prevent any long-term complications down the road, as far as permanent inflammation in the lungs.

The other thing that I tell them is we're going to use [treatment] only when the patient is having symptoms for 4 to 6 weeks. You can stop it afterwards. If they get sick again, or they get an illness or viral wheezing, you can go back on it again. They usually are okay with that. I usually don't tell the patient that they have to use this inhaled corticosteroid every single day, twice a day, for the whole year.

HCPLive: Are there specific red flags that make you stop and reconsider the asthma diagnosis entirely?

Arias: If both parents have a history of allergies or asthma, the child is likely to have asthma, and that also helps with the diagnosis. You do have to rule out other things.

The other thing that I see a lot [in] children, which gets missed a lot, is having reflux. I had a 7-year-old come to me with horrible asthma-like symptoms. I did a breathing test [and] the skin testing, [and] everything was normal. When I started asking, “What are you doing with mint? What about chocolate? What about caffeine?”

I put him on a regimen [and he] came back 6 to 8 weeks later. It was funny because the cough was all gone, all the symptoms were gone, and the first thing that the patient asked [was], when can I go back [to] eating chocolate again? He thought it was like, ‘okay, well, I avoided the chocolate and the mint and my Coke, and now I can go back and [consume] it again.’ I [told] him, ‘Well, if you want to go back and have symptoms.’ Once I said that, he understood.

HCPLive: For clinicians who don't specialize in this area, what's one thing you wish they were doing differently when they refer a wheezing preschooler to you?

Arias: I'm okay with the primary care doctor [and] the pediatrician treating the patient with a short-acting bronchodilator like albuterol, but if the patient is not controlled with that, [they] definitely [should be] referred to an allergist or pulmonologist. That's something that I would make sure that the primary care doctors do—at least try the short-acting bronchodilator before they refer them to me so that way I know what to do [as] the next step.

Editor’s note: Relevant disclosures for Arias include GENZYME CORPORATION, AstraZeneca Pharmaceuticals LP, Octapharma USA, Inc. Regeneron Healthcare Solutions, Inc., Takeda Pharmaceuticals U.S.A., Inc., BioCryst US Sales Co., LLC, PFIZER INC., Optinose US, Inc., CSL Behring, BioCryst US Sales Co., LLC, Novartis Pharmaceuticals Corporation, and more

References

1. GINA 2025 Asthma Update: More on T2 Biomarkers, Young Children, Revised Charts. Pulmonology Advisor. Published June 16, 2025. https://www.pulmonologyadvisor.com/features/gina-2025-asthma-update/

2. Bacharier L. Defining and Managing Preschool Asthma. Poster presented at the 2026 Eastern Allergy Conference (EAC) in Palm Beach, Florida, on Thursday, May 28.