14.2 Bronchiolitis, Croup & Community-Acquired Pneumonia

Bronchiolitis, croup, and community-acquired pneumonia are the acute pulmonology triad on clinical category #7. NHLBI asthma logic does not transfer. AAP bronchiolitis, pediatric croup care, and IDSA/PIDS CAP guidance decide the drug — or the decision to use no drug.

Quick Answer: Bronchiolitis is supportive: hydrate, suction, watch hypoxia; no routine albuterol, steroids, or CXR. Croup is a bark and stridor; give oral dexamethasone even for mild-to-moderate disease; add racemic epinephrine when there is resting stridor or distress, then observe. Immunized outpatient CAP is amoxicillin first-line; CXR is not required if the child is mildly ill and the diagnosis is clinical. Hypoxia, retractions, a toxic appearance, and infant apnea are ED red flags.

Bronchiolitis (AAP): supportive care is the treatment

Bronchiolitis is a viral lower respiratory infection of infants and toddlers, typically under 2 years. RSV is the classic winter pathogen; rhinovirus, human metapneumovirus, and parainfluenza cause the same picture. Copious rhinorrhea is followed by cough, tachypnea, wheeze and crackles, feeding difficulty, and retractions. Peak work of breathing is often days 3–5, which is why a child who “looked fine yesterday” can look worse at the 48-hour recheck.

Diagnosis is clinical. You do not need a viral PCR to manage a typical winter infant, and a positive RSV swab does not change AAP therapy. Do not treat bronchiolitis as bacterial pneumonia, asthma, or croup.

AAP recommendations the exam actually tests:

• No routine albuterol. A trial is not standard of care in typical bronchiolitis. Wheeze here is mucus and edema in small airways, not the bronchospasm of school-age asthma.
• No epinephrine as routine therapy.
• No corticosteroids. Systemic steroids do not improve typical viral bronchiolitis and add harm.
• No routine CXR. Films create false “infiltrate” reads and unnecessary antibiotics.
• No chest physiotherapy as routine care.
• No antibiotics unless a concurrent bacterial infection is specifically suspected.
• Hydrate. Small frequent feeds, nasal saline and suction before feeding, and a plan for poor intake.
• Watch hypoxia. Supplemental oxygen is for persistent hypoxemia (AAP commonly taught threshold: saturations persistently below 90% in previously healthy infants). Brief desaturations during sleep or feeding are not an automatic admission by themselves, but sustained hypoxia, marked retractions, dehydration, and apnea are.

Apnea is the infant-specific trap, especially in young infants and former preemies. Send that infant to the ED even if the lung exam is not dramatic.

Palivizumab is prevention for selected high-risk infants (extreme prematurity, some congenital heart disease, chronic lung disease) — not a treatment for established bronchiolitis. Hypertonic saline is not a primary-care default.

Croup: dexamethasone early; racemic epinephrine for resting stridor

Croup (laryngotracheobronchitis) is a viral upper-airway illness, classically parainfluenza, in children about 6 months to 3 years. The history is a cold followed by a barking, seal-like cough, hoarseness, and inspiratory stridor. The child is often worse at night. Subglottic edema produces the bark; the lung bases may be clear. A “steeple sign” on AP neck film is optional trivia — do not x-ray a typical, stable croup.

Severity is clinical. Stridor only when crying or active, with an alert toddler, normal vitals, and no resting retractions, is mild-to-moderate. Stridor at rest, retractions, agitation, or hypoxia is moderate-to-severe.

Dexamethasone is the disease-modifying drug. Give oral dexamethasone for even mild-to-moderate croup — a single dose (commonly taught 0.15–0.6 mg/kg, often 0.6 mg/kg, with a usual maximum in the 10–16 mg range depending on the protocol you practice under). Oral is preferred when the child can swallow; IM/IV if vomiting. You do not wait for the bark to become a crisis.

That is the PNCB-style item: an alert toddler with fever, barking cough, and stridor only when crying, with normal vitals, gets oral dexamethasone — not racemic epinephrine, not albuterol, and not amoxicillin.

Racemic epinephrine is for resting stridor or respiratory distress. It shrinks mucosal edema quickly. Observe for about 2–3 hours because rebound can occur; racemic epinephrine is not a parking-lot treatment and is not the first drug for the playful toddler whose stridor appears only with crying. Heliox and intubation are rare escalations.

Not croup therapy: albuterol (lower-airway drug), amoxicillin (viral illness), cool-mist tents as the only plan, or mistaking epiglottitis and bacterial tracheitis for garden-variety croup.

Community-acquired pneumonia: viral versus bacterial

Preschool CAP is often viral. School-age children add Mycoplasma (“walking pneumonia”: gradual onset, prominent cough, relatively well appearance). Streptococcus pneumoniae remains the leading typical bacterial pathogen in immunized children.

Immunized, mildly ill, outpatient CAP: high-dose amoxicillin is first-line (IDSA/PIDS; commonly 90 mg/kg/day divided). Amoxicillin covers pneumococcus. Azithromycin is not first-line for typical preschool CAP; reserve a macrolide when the picture is atypical in a school-age child or when you have a specific indication. Unimmunized or incomplete Hib/pneumococcal status, a very ill appearance, or suspected staphylococcal or complicated disease is a different, usually inpatient pathway.

CXR is not always required if the child is mildly ill, fully immunized, and you are treating empirically as outpatient CAP. Image when the diagnosis is uncertain, the child is hypoxemic or failing, or you suspect effusion or complication. Blood cultures are not routine for uncomplicated outpatient disease.

Influenza testing in season can change antiviral decisions. Do not stack azithromycin “for coverage” on every viral-looking preschooler with crackles.

Red flags — send to the ED

• Hypoxia or persistent desaturation
• Retractions with distress, grunting, head bobbing, or inability to speak/feed
• Toxic appearance, lethargy, poor perfusion
• Infant apnea or a young infant with bronchiolitis and a high-risk history
• Suspected epiglottitis, bacterial tracheitis, foreign body, or anaphylaxis
• Dehydration, inability to maintain intake, or a croup child who still has resting stridor after racemic-epinephrine observation

Exam traps

• Albuterol or prednisolone for typical bronchiolitis.
• Racemic epinephrine for mild croup with stridor only when crying — that child needs dexamethasone.
• Amoxicillin for croup.
• Azithromycin first for immunized preschool CAP.
• Mandatory CXR in mild, classic outpatient pneumonia.
• Sending home an infant with apnea or a hypoxic toddler because “it’s just a virus.”

Support bronchiolitis, steroid croup early, antibiotic the right CAP, and move the red-flag airway to the ED.