| Precipitating factor | Diagnosis | Management |
| Non-adherence to maintenance treatment | Careful sensitive history taking through the multidisciplinary team | Re-negotiating to treatment priorities, (rarely) child protection procedures |
| Viral infection | ||
| Respiratory syncytial virus | History—season. Immunofluorescence of NPA | Supportive. Adequate fluids and oxygen in infants. Intravenous antibiotics to treat secondary bacterial infection |
| Influenza | History—prevalence in sentinal sites. Immunofluorescence of NPA or throat swab | Antibiotic and supportive treatment plus specific neuraminidase inhibitors (Zanamavir or Oseltamivir) |
| Fungal infection/hypersensitivity | ||
| ABPA | Raised total IgE and aspergillus-specific IgE. New findings on chest radiograph | Oral prednisolone 0.5–1 mg/kg for 2–3 weeks and then taper. Itraconazole |
| Mucus plugging | ||
| Lobar/segmental collapse | Radiological | Consider ABPA. Intravenous antibiotics. Oral prednisolone. Targeted physiotherapy. If no response proceed to flexible bronchoscopy with bronchial lavage under direct division ± direct instillation of dornase alfa. Physiotherapist administered (“blind”) bronchial lavage |
| Atypical mycobacteria | ATS clinical and radiological criteria | Guided by specific organism. At least 3 drugs started sequentially. Treatment required for at least 12 months |
| Mycobacterium avium complex | Sputum culture | Clarithromycin, rifabutin, ethambutol |
| M abscessus/fortuitum | Cefoxtin, amikacin, clarithromycin | |
| M kansasii | Isoniazid, rifampicin, ethambutol |
ABPA, allergic bronchopulmonary aspergillosis; ATS, American Thoracic Society; NPA, nasopharyngeal aspirate.