🫁 Asthma – Most Common Cause of Recurrent Wheezing
• Diagnostic clues: nocturnal cough, triggered by colds/exercise/cold air/laughter, bronchodilator response
• Diagnosis after recurrent episodes; spirometry if possible
• Chest x-ray not needed for diagnosis (hyperinflation/atelectasis may be seen)
🦠 Bronchiolitis (Infants)
• RSV most common cause
• Prodrome of URI → profuse rhinorrhea, cough, wheezing, tachypnea
• Respiratory distress in young infants
• No routine antibiotics or bronchodilators (guidelines vary)
⚠️ Red Flags & Urgent Causes
• Choking history → foreign body (10-25% radiopaque, bronchoscopy if high suspicion)
• Anaphylaxis: wheezing + hives/angioedema after allergen exposure → epinephrine
• Vocal cord dysfunction: inspiratory stridor-like wheeze, unresponsive to bronchodilators, teenage girls, laryngoscopy during episode
🩺 Other Etiologies
• Mycoplasma/Chlamydophila pneumoniae: school-aged, fine crackles, wheeze
• Tracheomalacia/bronchomalacia: low-pitched, central wheeze, no bronchodilator response
• Primary ciliary dyskinesia: chronic sinopulmonary infections, situs inversus (Kartagener) in 50%
• Cystic fibrosis (newborn screen now, but clinically if negative screen and recurrent wheeze)
📌 Decision strategy: Acute wheezing + hives → anaphylaxis. Choking history → foreign body. Recurrent wheezing → asthma most likely, but consider VOCAL CORD DYSFUNCTION if no bronchodilator response. Most infants who wheeze will not wheeze later.