Predictors of ENT Referral and Microlaryngobronchoscopy Findings in Children With Recurrent Croup: A 10‐Year Cohort Study

Objective To determine predictors of ENT referral and microlaryngobronchoscopy (MLB) findings in children with recurrent croup. Design Retrospective cohort study. Setting Large district general NHS trust (2013–2023). Participants Children < 18 years with ≥ 2 croup episodes in 12 months or a clinician diagnosis of recurrent croup. Main Outcome Measures ENT referral, MLB performance and abnormal MLB findings. Results 128 children met recurrent croup criteria (median age 13.5 months, median 5 episodes). Sixty‐two (48%) were referred to ENT, of which 34 (55%) underwent MLB. Thirteen (38%) MLBs were normal. Abnormalities included subglottic stenosis ( n = 5), dynamic airway collapse ( n = 4), vocal‐cord pathology ( n = 3), non‐specific inflammatory/irritative change ( n = 3) and subglottic lesions ( n = 5), with the latter requiring surgical excision. Referred children were younger (median 12 vs. 17 months, p = 0.038) and had more episodes (median 5.5 vs. 4.0, p = 0.013). ENT referral correlated with ENT‐related conditions (26%, p < 0.001), gastro‐oesophageal reflux (24%, p = 0.021) and recurrent viral infections (47%, p = 0.022). MLB was more common with ENT‐related conditions (38%, p < 0.001) and reflux (32%, p = 0.003). After adjustment, only episode count predicted ENT referral (aOR 1.09 per episode, 95% CI: 1.01–1.19), no factor predicted MLB or abnormal findings. Conclusions ENT review is warranted for recurrent croup, whereas MLB should be reserved for children with red‐flag features suggesting significant airway pathology. Although most scoped children had normal or conservatively managed findings, a meaningful minority had clinically important abnormalities, including subglottic lesions requiring surgical intervention. Conventional risk factors offer little predictive value, supporting prospective multi‐centre studies to refine risk‐stratification.