Why does this matter for parents?

Many parents genuinely believe that switching from cigarettes to e-cigarettes protects their children. Dr. Brian Jenssen, associate professor of pediatrics at Children's Hospital of Philadelphia and one of the study's authors, addressed that assumption directly.

"Many parents believe e-cigarettes are a safer alternative to cigarettes, both for themselves and for their children's health," he said. "Our findings suggest that assumption doesn't fully hold up for kids with asthma."

Jenssen was blunt about what families should take away. "There is no safe level of tobacco or e-cigarette exposure when it comes to children," he said. "Parents and caregivers who use any tobacco or nicotine products should make every effort to quit, using evidence-based options like varenicline, nicotine replacement therapy and counseling."

Varenicline is a prescription medication that reduces nicotine cravings and the pleasure of smoking. Nicotine replacement therapy covers products such as patches, gums, and lozenges that deliver controlled doses of nicotine without the harmful byproducts of combustion.

What should pediatricians do differently?

The study has practical implications for how doctors run routine asthma care. Jenssen said the results reinforce the need for pediatric care teams to screen for all forms of household nicotine and tobacco use—not just cigarettes—and to offer cessation support for both as part of standard asthma management.

That screening step matters because a parent who has quit cigarettes but taken up vaping might answer "no" to a simple question about smoking. Without asking specifically about e-cigarettes, a care team could miss a household exposure that the study links to worse asthma outcomes.

How strong is the evidence?

Some caveats are worth keeping in mind. The study is cross-sectional, meaning it captures a snapshot of exposures and asthma control at a single point in time rather than tracking children over months or years. This design shows associations between household nicotine use and asthma outcomes, but it cannot prove that the exposure directly causes the flare-ups.

The data also rely on parent reports of household tobacco and e-cigarette use, which may not capture every exposure with perfect accuracy. Parents may underreport use, forget details, or be unaware of vaping by other household members.

Still, the scale of the study strengthens its findings. More than 48,000 clinic visits over nearly three years, drawn from a diverse pediatric network, give the researchers a broad picture of real-world household exposure. And the consistency of the pattern—more flares, more symptoms, more medication use, more admissions in exposed children—points in a clear direction.

The bottom line

For families managing a child's asthma, the message is practical: anything that puts nicotine and aerosol byproducts into the home air is a potential problem. E-cigarettes do not produce the same smoke as burning tobacco, but they are not harmless bystanders either. Children with asthma exposed to vaping at home had more flares and more symptoms that interfered with physical activity.

The researchers presented their work at the American Academy of Pediatrics 2026 National Conference & Exhibition in San Diego, and the full study appears in the American Journal of Respiratory and Critical Care Medicine (DOI: 10.1093/ajrccm/aamag162.6512), authored by B. Jenssen and colleagues as abstract B98-01.