Management of Infectious Bronchiolitis in Adults
Antibiotics should only be used in adults with infectious bronchiolitis when a bacterial infection is suspected or confirmed, as most cases are viral in origin and do not benefit from antibiotic therapy. 1
Diagnosis and Assessment
- Clinical Presentation: Infectious bronchiolitis in adults presents with cough (lasting up to 6 weeks), which may be productive or non-productive, and is often accompanied by mild constitutional symptoms 1
- Diagnostic Workup:
- High-resolution CT (HRCT) scan with expiratory cuts is essential to identify direct signs (dilation, airway wall thickening, nodular branching, "tree-in-bud" pattern) or indirect signs (mosaic attenuation) of bronchiolar disease 1
- Spirometry with bronchodilator testing, lung volumes, and gas exchange assessment 1
- Bronchoscopy may be necessary to rule out infection and obtain samples for culture 1
- Surgical lung biopsy should be considered when clinical syndrome, physiology, and HRCT findings do not provide a confident diagnosis 1
Determining Bacterial vs. Viral Etiology
- More than 90% of acute bronchitis cases in otherwise healthy adults are caused by viruses 1
- Common viral causes include rhinovirus, coronavirus, adenovirus, influenza virus, and respiratory syncytial virus 2, 3
- Common bacterial pathogens include Mycoplasma pneumoniae (most common), Haemophilus influenzae, and Streptococcus pneumoniae 3
- Important: Purulent sputum or change in sputum color (green or yellow) does not signify bacterial infection; purulence is due to inflammatory cells or sloughed mucosal epithelial cells 1
Management Approach
1. Supportive Care (First-line)
- Assess hydration status and provide IV fluids if oral intake is compromised 1
- Provide supplemental oxygen when SpO₂ falls persistently below 90% 1
- Consider symptomatic relief with:
- Cough suppressants (dextromethorphan or codeine)
- Expectorants (guaifenesin)
- First-generation antihistamines (diphenhydramine)
- Decongestants (phenylephrine) 1
2. Antimicrobial Therapy
- Viral Bronchiolitis: No antibiotics indicated 1
- Bacterial Bronchiolitis: Prolonged antibiotic therapy is recommended 1
- Choose antibiotics based on suspected pathogen and local resistance patterns
- For Mycoplasma or Chlamydophila: Macrolides or doxycycline
- For H. influenzae or S. pneumoniae: Amoxicillin-clavulanate or respiratory fluoroquinolone
3. Interventions NOT Recommended
- Routine antibiotic treatment in the absence of suspected bacterial infection 1
- β-Agonists (albuterol) for patients without asthma or chronic obstructive lung disease 1
- Chest physiotherapy is not recommended for routine management 1
Special Considerations
- Rule out pneumonia in patients with tachycardia (heart rate >100 beats/min), tachypnea (respiratory rate >24 breaths/min), fever (oral temperature >38°C), or abnormal chest examination findings (rales, egophony, tactile fremitus) 1
- For toxic/antigenic exposure or drug-related bronchiolitis, cessation of the exposure or medication plus corticosteroid therapy for those with physiologic impairment is appropriate 1
- Monitor for acute otitis media, which may develop as a complication and require separate management 1
Prognosis
Most adult patients with infectious bronchiolitis improve with appropriate management, and development of post-infectious bronchiolitis obliterans is rare 3. However, close monitoring is essential, particularly in patients with underlying cardiopulmonary disease or immunodeficiency.