Don't Ignore Mild Asthma in Children

Mild asthma is not benign. Underdiagnosis in children exposes them to preventable morbidity — including impaired lung growth that can lead to fixed airway obstruction and a higher lifetime risk for chronic obstructive pulmonary disease (COPD), as well as severe exacerbations and increased need for systemic corticosteroids. Experts at the 21st Francophone Allergy Congress 2026 said preserving respiratory function depends on early diagnosis and disease control.

Mild asthma is retrospectively defined as the level of treatment required to achieve and maintain disease control. It corresponds to asthma controlled with a low dose of inhaled corticosteroids or with a combination of inhaled corticosteroids and formoterol as needed (Global Initiative for Asthma(GINA)/French Society of Pediatric Pulmonology and Allergology, steps 1-2).

Mélisande Bourgoin-Heck, MD, PhD, Department of Pediatric Allergology, Armand Trousseau University Hospital, Sorbonne University, AP-HP, Paris, France, emphasized a fundamental distinction: “While control is based on symptoms, exacerbations, activity limitations, and quality of life, severity corresponds to the level of treatment required to achieve this control. The term mild therefore depends on the treatment required and not solely on the frequency or intensity of symptoms.”

How to Identify It?

Clinically, asthma most often presents with wheezing, cough, shortness of breath, and chest tightness, with symptoms that fluctuate in frequency and severity. Nighttime symptoms are common. Symptoms often start or worsen with viral infections, physical exertion (including after exercise), laughter, or exposure to allergens or cold air. “Symptoms are often dismissed as minor and intermittent,” the pediatrician said, “which leads to delayed diagnosis.”

That’s why recognizing risk factors is important because they help guide diagnosis: male sex, a first-degree family history of asthma, exposure to secondhand smoke, prematurity, maternal obesity, living in group settings or having school-aged siblings which raise the risk for early infections, a history of severe bronchiolitis, and an atopic tendency, demonstrated by atopic dermatitis, allergic rhinitis, or sensitization to food and respiratory allergens.

How Much Should We Trust Predictive Scores?

Several clinical scores for predicting asthma exist, notably the Asthma Predictive Index, the modified Asthma Predictive Index, and the Pediatric Asthma Risk Score; the latter demonstrates better overall discrimination, making it useful for children at low-to-moderate risk.

“These scores place significant emphasis on the atopic predisposition,” noted Bourgoin-Heck, “including allergic sensitivities, allergic rhinitis, and atopic dermatitis. Their performance varies by age and clinical phenotype. They are highly specific for the diagnosis of allergic asthma, with a positive score associated with a high risk of asthma. However, their sensitivity is not up to par: A negative score does not rule out the diagnosis, leading to a risk of overlooking nonallergic forms.”

A chest x-ray is used to rule out differential diagnoses. It may be normal or reveal chest distension or bronchial signs. During follow-up, it is only recommended in cases of fever or severe illness to look for complications such as bronchopulmonary superinfection, pneumothorax, pneumomediastinum, subcutaneous emphysema and ventilation disorders/atelectasis.

Normal Spirometry: Could Asthma Really be Ruled Out?

Pulmonary function tests (PFTs) may be normal and do not rule out asthma. Spirometry can be performed around age 6 years and is often normal. “The reversibility test is a diagnostic indicator but may be negative in cases of normal forced expiratory volume in 1 second (FEV₁),” warned the specialist.

Provocation tests are useful in cases of doubt.

In children unable to perform a forced exhalation, spirometry is impossible or unreliable, which justifies the use of respiratory resistance measurements (starting at age 3). Several methods are then used: flow-interruption resistance (FIR) identifies bronchial obstruction with an expiratory FIR > 2 Z scores (how many SDs a result is from the predicted value for a child’s age/height/sex). Oscillometry, suitable for young children, is considered pathologic for values exceeding 150% of the predicted value. Plethysmography indicates obstruction with a Raw value > 150% of the predicted value or an sRaw value > 180%.

Interpretation is based on standards adapted to the technique and the study population, with thresholds varying by method (threshold values for PFTs, page e4).

When in Doubt, How Useful Are Biomarkers?

As a biomarker of atopy, a blood eosinophil count of at least 150/mm³ is associated with asthma symptoms and exacerbations. Specific Immunoglobulin E (IgE) indicates allergic sensitization associated with asthma. Finally, elevated fractional concentration of exhaled nitric oxide (> 20-25 parts per billion depending on age) is associated with wheezing, corticosteroid use, and persistent asthma. The combination of atopy markers — including maternal allergy, eczema, wheezing, positive specific IgE levels, and eosinophilia — significantly increases the likelihood of asthma.

“However, when diagnostic uncertainty persists in a child younger than 5 years (absence of atopy; normal PFTs — which is common), a trial of treatment based on initial symptoms may be recommended according to GINA 2025 (Box 10-2),” explained Bourgoin-Heck.

In the presence of mild and intermittent symptoms, a short-acting bronchodilator challenge test on demand is indicated for a maximum duration of 2-3 months. This strategy applies to infrequent wheezing episodes, without the need for emergency care and therefore without any severe exacerbations, with symptoms occurring twice or less per week. Treatment consists of administering two puffs when symptoms occur (to be repeated as needed), with an assessment of improvement within 20-60 minutes. In cases of a history of a severe wheezing episode within the past year (systemic corticosteroids, emergency department visit, and hospitalization) or symptoms more than twice a week, the therapeutic trial involves long-term inhaled corticosteroids (eg, fluticasone 100 µg/d to 250 µg/d) combined with a short-acting bronchodilator as needed for 2-3 months. If the response is favorable, treatment is adjusted to the minimum effective dose.

Monitoring of clinical progress relies on asthma control scores such as the Asthma Control Test, considering both parental perception and the child’s self-assessment. Because the goal in mild asthma is indeed to achieve complete control.

Mild Asthma: Behind the Triviality, Real Risks

Mild childhood asthma is the most common form of asthma. It is by no means benign and carries a risk for exacerbations requiring systemic corticosteroids and potential long-term consequences.

Asthma is often missed — an estimated 20% of children age ≥ 6 years to 70% by age 1 year are not identified — and therefore go untreated, leading to a lower quality of life from attacks and persistent symptoms between episodes that could limit activity and disrupt sleep.

Even seemingly mild asthma is associated with a risk for severe exacerbation, including in patients with infrequent and mild symptoms.

There is also impaired lung growth, with a decrease in peak lung function and the potential for progression to fixed bronchial obstruction, which can lead to COPD. However, it has been shown that early treatment reduces chronic inflammation, limits bronchial remodeling, and prevents the decline in lung function.

In a Danish neonatal cohort 9125 infants, were followed at 1, 3, and 6 years of age and analyzed at 50 years of age via the Danish COPD patient registry, early asthma symptoms were associated with a decrease in FEV1 (-3.36%) and the FEV1/ Forced Vital Capacity ratio (-1.28), as well as an increased risk for a COPD diagnosis in adulthood (odds ratio [OR], 1.96).

Epidemiologic data confirm this: A history of asthma increases the risk of developing COPD by 10-30 times, and a reduced peak FEV1 in early adulthood is associated with an increased risk for early‑onset COPD and greater severity.

“Asthma is associated with a decline in lung function that can begin as early as infancy,” noted the pediatrician, “or even during the prenatal period, persists throughout childhood, continues into adulthood, and predisposes individuals to established bronchial obstruction.”

Early Inhaled Corticosteroids Reduced Exacerbations

In the inhaled steroid treatment as regular therapy in early asthma trial, which enrolled about 7000 adults and children and included a subgroup of 1900 children aged < 11 years with recent-onset mild asthma, inhaled budesonide was compared with placebo. Over 3 years of follow-up, the placebo group showed poorer lung function, whereas those treated with budesonide had improved FEV1 and about a 40% reduction in severe exacerbations. A partial functional “catch-up” was observed when treatment was initiated in the third year.

However, the study does not allow for conclusions regarding the very long-term prevention of functional decline, due to the lack of sufficient follow-up time.

Delayed Treatment Increases Risks

Furthermore, delayed treatment is associated with an increased use of short-acting bronchodilators and systemic corticosteroids, carrying a risk for complications. The specialist warned: “Adverse effects appear after just a few courses of oral corticosteroids, notably an increased risk of fractures (odds ratio, 2.15 for low doses of prednisolone < 70 mg; OR, 3.09 for higher doses > 70 mg). These risks are real and emerge quickly.”

Another study confirms the adverse effects of oral corticosteroid therapy: A cumulative dose of 500 mg to 1000 mg (approximately four to five courses of systemic corticosteroids over a lifetime) already increases the risk. Complications include osteoporosis, diabetes, cataracts, heart failure, and pneumonia. “Cumulative exposure, even intermittent, is associated with increased morbidity, which can be prevented through appropriate management of mild asthma,” she added. “Yet it has been clearly demonstrated that inhaled therapy reduces the need for oral corticosteroids.”

This story was translated from Medscape’s French edition.

A version of this story first appeared on Medscape.com.