Background and aims Current evidence does not support a clinically relevant effect of systemic glucocorticoids in reducing length of hospitalisation (LOS) in acute bronchiolitis. To evaluate whether treatment with oral corticosteroids prior to admission (CO) decreases LOS in patients admitted for acute moderate bronchiolitis (MB).

Material and methods In a context of a randomised, controlled, double-blind clinical trial, 185 patients with MB were included and grouped in receiving CO before admission for more than 24 h or not. Patients who received corticosteroids during hospitalisation and patients with risk factors for severe bronchiolitis were excluded. LOS as the main variable was recorded. Secondary: clinical scale, respiratory rate and oxygen saturation on admission.

Results 26.5% received corticosteroids before to admission. Demographic and clinical data were similar (p > 0.05): Males (47% vs 51%), exclusively breastfeeding (51% vs 56%), or RSV positive (61% vs 60%), parental smoking (45% vs 39%) and atopy (38% vs 28%). There were statistically significant differences in mean age (3.5 vs 1.7 months, p = 0.000), severity clinical scale (5,37 vs 4.93 points, p = 0.021) and in receiving salbutamol (85.7% vs 19.1%, p = 0.000). There was no difference in respiratory rate (p = 0.584) or oxygen saturation on admission (p = 0.07). The LOS was 2.43 vs 3.22 days, p = 0.004.

Conclusions In our series, CO administration before admission to BA decreases LOS significantly. The CO group was older but more severe; both can be a confusion factor.