Bronchiolitis and Crackles
Yes, bronchiolitis commonly presents with crackles (rales), which are a characteristic clinical finding along with wheezing, tachypnea, and increased respiratory effort. 1
Clinical Presentation
The American Academy of Pediatrics guideline explicitly lists rales (crackles) as one of the core clinical signs and symptoms of bronchiolitis, alongside rhinorrhea, cough, tachypnea, wheezing, and increased respiratory effort 1. More recent literature confirms that bronchiolitis variably presents with diffuse crackles and inflammatory wheezing 2.
Age-Related Variation in Findings
Important caveat: The presence of crackles varies significantly by age:
- Infants younger than 4 months are more likely to present without any chest signs on auscultation 3
- Infants older than 6 months are more likely to present with wheeze 3
- Infants presenting without any auscultatory chest signs were significantly younger (mean 15.1 weeks) compared to those with chest signs (mean 24.4 weeks) 3
This age-dependent variation is a common pitfall—don't dismiss bronchiolitis in very young infants just because crackles are absent on examination.
Clinical Significance of Crackles
Crackles correlate with disease severity. Research demonstrates that crackles (along with cyanosis) most closely correlate with oxygen requirements during hospitalization and overall disease severity 4. Additionally:
- Crepitant crackles are significantly associated with:
Practical Assessment Points
When examining an infant with suspected bronchiolitis:
- Count respiratory rate over a full minute for accuracy 1
- Consider suctioning and positioning before examination, as upper airway obstruction can obscure lower airway findings 1
- Recognize that physical findings are temporally variable—serial examinations may be needed 1
- The viral pathogen (RSV, influenza, rhinovirus, etc.) does not influence which auscultatory signs are present 3
Use pulse oximetry as your most reliable initial assessment tool, as it correlates closely with cyanosis and oxygen requirements, and is more predictive than respiratory rate alone 4.