BACKGROUND: Children's interstitial lung disease (chILD) is a rare and potentially life-threatening condition. For many chILD conditions, systemic corticosteroids (sCCS) are considered the primary treatment despite a broad spectrum of potential side effects.

AIM: We aimed to determine the long-term effects of sCCS treatment on growth, bone mineral density (BMD), and body composition after chILD.

MATERIALS AND METHODS: This descriptive cross-sectional single-center study included patients diagnosed with chILD before the age of 18 years treated with sCCS in the period 1998-2020. Dual-energy X-ray absorptiometry, anthropometric measurements, bone age determination, and blood tests were performed in 53 (55% males) of 89 eligible patients.

RESULTS: Median (range) age was 19.3 (6.4;30.7 years). Participants received a median (range) cumulative sCCS dose of 1144 (135; 6178) mg over a 2.0 (0.1; 13.8) years period and latest dose was administered 11.7 (1.2; 19.6) years before follow-up. Mean delta height (height standard deviation scores [SDS] - target height SDS) was reduced at sCCS treatment initiation (mean: -0.55, 95% confidence interval [CI]: -0.91; -0.20, p < .005) and at sCCS treatment cessation (mean: -0.86, 95% CI:-1.22; -0.51, p < .001), but normalized in the majority at follow-up (mean: -0.29, 95% CI:-0.61; 0.03, p = .07). Mean (SD) BMD z-score for the spine and whole body was -0.34 (1.06) and 0.52 (1.13), with no significant correlation to sCCS dose. Excess body fat (>30% in females, >25% in males) was found in 58% of patients.

CONCLUSION: Long-term treatment with sCCS did not cause significant long-term reduction of height but showed subtle effects on fat mass percentage and BMD. Given the severity of chILD, the observed long-term effects of sCCS on growth and BMD appear acceptable.