Teague WG, Lawrence MG, Williams S, et al. - Since corticosteroid-refractory recurrent wheeze in preschool children is a difficult dilemma for practising clinicians, and guidelines for alternative treatments for this population are unclear, researchers sought to identify clusters of preschool children with treatment-refractory wheeze using unsupervised analysis of lung lavage (BAL) variables. Bronchoscopy with BAL was performed on 155 children ≤ 6 years of age to assess airway structure, inflammatory markers, and pathogens. Airway malacia, gastroesophageal reflux, indolent human rhinovirus (HRV) bronchoalveolitis, and type-2 ^high inflammation are four clusters of preschool children with recurrent wheeze refractory to inhaled corticosteroids treatment. The findings support the risk and expense of invasive bronchoscopy in preschool children for diagnosing causes of treatment-refractory wheeze and developing novel therapies targeting airway malacia, HRV infection, and BAL neutrophilia.