A new study from Seoul National University Bundang Hospital (SNUBH) has found that steroid treatments commonly used for childhood asthma may raise fracture risk by up to threefold, underscoring the need for precise diagnosis and careful treatment adjustments throughout childhood.

Childhood asthma is a chronic inflammatory respiratory disease that requires lifelong management. Treatment typically involves inhaled steroids delivered through inhalers or nebulizers, which act locally in the lungs to reduce inflammation and ease symptoms.

Systemic steroids are reserved for acute exacerbations or cases in which symptoms are not adequately controlled, and are administered orally or via injection, affecting the entire body’s immune response.

Concerns about steroid effects on bone health have persisted for years, given evidence suggesting that steroid exposure may reduce bone density.

However, the specific relationship between fracture risk and the type, amount, and timing of steroid use in children has not been clearly defined. Since childhood is a critical period for bone growth and development, understanding this association has been considered especially important.

To address this gap, the SNUBH team, led by Professor Kim Kyung-hoon of the Department of Pediatrics, conducted an analysis using the National Health Insurance Service (NHIS) sample cohort.

The researchers examined data from a birth cohort of 30,000 children born between 2002 and 2004, ultimately identifying 2,324 children diagnosed with asthma after age six and matching them with 10,950 non-asthmatic controls using propensity score matching based on sex, socioeconomic factors, birth region, and comorbidities.

Both cohorts were tracked from birth to age 15. Fracture incidence after inhaled steroid use was evaluated across three time windows -- within 90 days, 91 to 180 days, and 181 to 365 days. Systemic steroid users were categorized into low-dose and high-dose groups based on the lowest and highest 25 percent of cumulative use.

Inhaled steroid use was associated with a threefold increase in fracture incidence within 90 days compared to children without asthma, with elevated risk also observed across the other time windows.

For systemic steroids, fracture risk was 2.15 times higher in the low-dose group and 3.09 times higher in the high-dose group, clearly demonstrating a dose-dependent pattern. Independently of steroid exposure, children with asthma had a 22 percent higher overall fracture risk than non-asthmatic peers.

The study provides one of the most detailed comparisons to date of fracture risk by steroid type and exposure pattern in children with asthma. It highlights the importance of individualized treatment plans that consider both long-term disease control and bone health.

Kim emphasized that the findings should not deter appropriate steroid use, noting that avoiding steroids out of concern for side effects could worsen asthma control.

“Because of reports that steroids raise fracture risk, some people may try to avoid steroids altogether, but that can actually worsen asthma control,” Kim said. “When asthma is suspected in a child, it is important to select treatments based on accurate specialist evaluation and testing, and then adjust the dose and duration through regular follow-up.”

The study was published in the international journal Pediatric Allergy and Immunology.