Bronchiolitis is the most common lower respiratory tract disease in infants, and RSV (Respiratory syncytial virus) bronchiolitis is the leading cause of hospitalization in infants. It will infect 90% of children by 2 years of life.
Bronchiolitis "season" in the US is typically December to March but it does occur year round.
Pathology is caused by respiratory epithelial cell death that results in inflammation, edema, smooth muscle contraction, bronchoconstriction and mechanical obstruction by cellular debris and mucus plugging.
History that suggest Bronchiolitis is cough, rhinorrhea, fever
Most common PE findings are runny nose, tachypnea, wheezing, cough, crackles, use of accessory muscles, and/or nasal flaring.
Respiratory distress, dehydration, sepsis, and RSV associated apnea are feared severe complications.
RSV associated apnea may be the presenting symptom in some infants.
Infants at greatest risk for this are younger (usually < 3 months), hx of prematurity, hx of apnea of prematurity, and those who are early on in the illness.
Bronchiolitis:Diagnosis and Treatment of an Increasingly Common Seasonal Presentation. Pediatric Emergency Medicine Reports. Nov 2008. Volume 13, Number 11