Croup (Laryngotracheobronchitis)

Croup is a common pediatric upper airway illness caused by subglottic inflammation, most often from parainfluenza virus, affecting ~3% of children aged 6 months to 3 years. It presents with the classic triad of barking (seal-like) cough, inspiratory stridor, and hoarseness, with symptoms characteristically worse at night. [1-3] The following figure from the AAFP provides a management algorithm stratified by severity:

• HPI essentials: Onset and duration of barking cough, stridor (at rest vs. with agitation only), hoarseness, respiratory difficulty, and fever
• Prodrome: Typically 1–3 days of URI symptoms (rhinorrhea, coryza, low-grade fever) before the barking cough begins [3]
• Timing: Abrupt onset at night is classic; symptoms often worsen with agitation and crying [3-4]
• Severity markers: Ability to drink/eat, sleep disruption, activity level, degree of respiratory distress
• Prior episodes: Recurrent croup (≥2 episodes/year) should raise concern for underlying anatomic abnormality, GERD, or atopy [1]
• Important negatives: Choking/foreign body ingestion history, drooling, dysphagia, immunization status (Hib), toxic appearance, rash

• Stridor at rest (indicates moderate-to-severe obstruction)
• Suprasternal/sternal retractions, nasal flaring, accessory muscle use
• Cyanosis or SpO₂ <92%
• Lethargy, altered consciousness, or decreased responsiveness [3][5]
• Drooling, inability to swallow, tripod positioning → think epiglottitis [1][6]
• Toxic appearance, high fever, failure to respond to standard therapy → think bacterial tracheitis [6]
• Sudden onset without prodrome or fever → think foreign body or angioedema [6-7]
• Biphasic stridor (inspiratory + expiratory) suggests more severe or fixed obstruction

• First-line — Corticosteroids (all severities):
  • Dexamethasone 0.6 mg/kg PO (single dose, max 12 mg) — most studied and recommended [1][4][7]
  • Prednisolone is an acceptable alternative [1]
  • Onset of benefit ~30 minutes; full effect over hours [3][8]
• Moderate-to-severe — Nebulized epinephrine:
  • Racemic epinephrine 0.5 mL of 2.25% in 4.5 mL NS, or L-epinephrine 5 mL of 1:1000 [7]
  • Rapid onset but short-lived (~2 hours); must observe 2–4 hours post-treatment for rebound [1]
• Not indicated: Antibiotics (unless bacterial superinfection suspected), albuterol, cough suppressants
• No proven benefit: Humidified mist therapy [8-9]
• Adjunct with emerging evidence: Exposure to outdoor cold air (<50°F) for 30 minutes combined with dexamethasone may reduce symptoms in mild-to-moderate croup [1]

• Encourage clear fluids to maintain hydration; avoid forcing oral intake if child is in significant distress
• Small, frequent sips preferred over large volumes
• No specific dietary triggers or restrictions apply
• Assess for dehydration if poor oral intake has been prolonged

• Respiratory: Cough character (barking vs. productive), stridor timing, work of breathing, apneic episodes
• ENT: Hoarseness, drooling, dysphagia, sore throat, ear pain
• Constitutional: Fever (typically low-grade; high fever → consider bacterial tracheitis/epiglottitis), irritability, lethargy
• GI: Vomiting (from coughing paroxysms), feeding difficulty, reflux symptoms (if recurrent croup)
• Skin: Rash (consider measles croup in unimmunized, urticaria if angioedema)

• Collateral: Caregiver description of cough sound, witnessed choking events, sick contacts, daycare exposure
• Family history: Atopy, asthma, recurrent croup in siblings (associated with airway hyperreactivity) [1][3]
• Immunization status: Hib vaccine (epiglottitis risk in under-immunized), diphtheria vaccine (laryngeal diphtheria in unimmunized) [1][6]
• Social context: Daycare attendance (viral exposure), secondhand smoke exposure

• Age: Peak incidence in the second year of life; range 6 months to 6 years [2-3]
• Sex: Male predominance (1.5:1) [3]
• Season: Peak in autumn/winter (October–November) [1][3]
• Prematurity or history of neonatal intubation (subglottic stenosis risk)
• Underlying airway abnormalities: Subglottic stenosis, tracheobronchomalacia, laryngomalacia [1]
• Atopy/asthma: Children with ≥2 episodes of croup before age 4 have high incidence of asthma and allergies [3]
• GERD — strongly associated with recurrent croup [1]

Cannot-miss dangerous diagnoses: [1][6-7]

• Epiglottitis — High fever, drooling, dysphagia, tripod position, muffled voice, NO barking cough; under-immunized for Hib
• Bacterial tracheitis — Toxic-appearing child, high fever, worsening after initial URI, fails to respond to nebulized epinephrine; most common pathogen is S. aureus
• Foreign body aspiration — Sudden onset, no prodrome/fever, history of choking; no barking cough
• Retropharyngeal abscess — Neck stiffness, dysphagia, drooling, unilateral cervical adenopathy
• Peritonsillar abscess — Trismus, "hot potato" voice, unilateral tonsillar swelling

Other considerations:

• Angioedema/allergic reaction — Rapid onset, possible urticaria, history of allergy
• Laryngeal diphtheria — Unimmunized, gradual onset, pharyngeal membrane
• Subglottic stenosis — Recurrent or atypical presentations
• Laryngotracheobronchopneumonia — Lower airway signs (crackles, wheezing), radiographic pneumonia [7]

• Previous croup episodes (frequency, severity, need for intubation)
• History of neonatal intubation or airway surgery (subglottic stenosis)
• Asthma, reactive airway disease, atopy
• GERD
• Congenital airway anomalies (laryngomalacia, tracheomalacia, vascular ring)
• Immunodeficiency (consider atypical infections)
• Immunization history (Hib, diphtheria)

• Vitals: Tachypnea, tachycardia (may reflect distress or fever); SpO₂ (cyanosis is a late finding); temperature
• General: Level of distress, position of comfort, ability to interact, consolability — keep the child calm; agitation worsens obstruction [3]
• Airway/ENT: Barking cough quality, inspiratory stridor (at rest vs. with agitation), hoarseness; look for drooling or dysphagia (suggests epiglottitis)
• Chest: Suprasternal, intercostal, and subcostal retractions; air entry (decreased = severe); biphasic stridor
• Abdomen: Assess hydration status
• Skin: Color (pallor, cyanosis), rash

Westley Croup Score (0–17 points) — used for severity stratification: [3][7]

• Mild: Westley score <4 (~85% of cases) — barking cough, no stridor at rest
• Moderate: Westley score 4–6 — stridor at rest, mild retractions
• Severe: Westley score >6 — stridor at rest, marked retractions, decreased air entry, ± altered consciousness [3][7]

• Labs are typically unnecessary for diagnosis of croup [1-2]
• Viral cultures and rapid antigen testing have minimal impact on management and are not routinely recommended [2]
• If bacterial superinfection suspected (toxic appearance, failure to improve): CBC with differential (leukocytosis with bandemia), blood cultures, CRP [7]
• If dehydration is a concern: BMP
• Rapid influenza testing may be considered in appropriate season if it would change management [7]

• Imaging is not routinely indicated for typical croup [1-2]
• AP neck radiograph: Classic "steeple sign" (subglottic narrowing) — sensitivity is limited; useful when diagnosis is uncertain [2][10]
• Lateral neck radiograph: Helpful to evaluate for epiglottitis (thumbprint sign), retropharyngeal abscess (prevertebral soft tissue widening), or foreign body [6-7]
• Chest radiograph: Consider if lower airway involvement suspected (laryngotracheobronchopneumonia) [7]
• CT neck with contrast: Reserved for suspected deep space neck infections (retropharyngeal/peritonsillar abscess)
• Avoid imaging in severe distress — prioritize airway management

• Westley Croup Score: Primary severity stratification tool (see Physical Exam section above) [3][7]
• Pulse oximetry: Continuous monitoring in moderate-to-severe cases
• Laryngoscopy/bronchoscopy: Reserved for atypical presentations, recurrent croup, or suspected anatomic abnormality; NOT indicated in acute setting unless airway intervention needed [1-2]
• Triple endoscopy (laryngoscopy, bronchoscopy, esophagoscopy): Recommended for children <3 years with recurrent croup and high suspicion for airway abnormality; most common findings include reflux changes, subglottic stenosis, and tracheobronchomalacia [1]

• ECG is not routinely indicated in croup
• Consider if there is unexplained tachycardia out of proportion to fever/distress, or if multiple doses of nebulized epinephrine have been administered (monitor for arrhythmia)
• Continuous cardiorespiratory monitoring is appropriate for children receiving nebulized epinephrine

Croup is a clinical diagnosis based on the characteristic barking cough, inspiratory stridor, and hoarseness, typically preceded by 1–3 days of URI symptoms in a child aged 6 months to 3 years. [1-3] Approximately 85% of cases are mild, with only 1–8% requiring hospitalization and <3% of admitted patients requiring intubation. [7][9]

Severity stratification drives management

• Mild (Westley <4): Barking cough, no stridor at rest → dexamethasone alone, discharge home
• Moderate (Westley 4–6): Stridor at rest, chest wall retractions → dexamethasone + nebulized epinephrine, observe
• Severe (Westley >6): Marked retractions, decreased air entry, altered consciousness → aggressive treatment, possible ICU [3][7]

Complications to consider: respiratory failure requiring intubation, bacterial superinfection (laryngotracheobronchitis/laryngotracheobronchopneumonia), pulmonary edema (rare, post-obstructive). [7]

All severities — Corticosteroids

• Dexamethasone 0.6 mg/kg PO × 1 dose (max 12 mg) — standard of care [1][4][7]
• Can be given IM or IV if unable to tolerate PO
• A Cochrane review of 43 RCTs (4,565 children) confirmed glucocorticoids reduce symptoms at 2 hours, shorten hospital stays, and reduce return visits (NNT = 7) [4][11]

Moderate-to-severe — Add nebulized epinephrine

• Racemic epinephrine 0.5 mL of 2.25% in 4.5 mL NS, or L-epinephrine 5 mL of 1:1000 via nebulizer [7]
• May repeat as needed for persistent/recurrent stridor [5]
• Observe 2–4 hours post-treatment for symptom recurrence [1]

Severe/impending respiratory failure

• Supplemental oxygen for hypoxia
• Repeated nebulized epinephrine
• Consider heliox (70:30 helium-oxygen) — limited evidence of benefit but may reduce work of breathing [3]
• Prepare for advanced airway management if deteriorating [5]
• If bacterial superinfection suspected: IV antibiotics (vancomycin + cefotaxime) and likely intubation [7]

Adjunctive

• Keep child calm — minimize agitation (worsens obstruction)
• Cold outdoor air exposure (<50°F for 30 min) combined with dexamethasone may reduce symptoms in mild-to-moderate croup [1]
• Humidified mist has no proven benefit [8-9]

• Discharge home (mild croup): Westley score <2 after treatment, no stridor at rest, tolerating PO, reliable caregiver, close follow-up available [12]
• ED observation: Westley score 2–5 after dexamethasone; observe for improvement over 2–4 hours; if improved and no stridor at rest, may discharge [6]
• Admission criteria: [1][6]
  • Persistent stridor at rest after corticosteroids and epinephrine
  • Requiring ≥2 doses of nebulized epinephrine
  • SpO₂ <92% on room air
  • Toxic appearance or altered mental status
  • Inability to tolerate oral fluids
  • Unreliable follow-up or caregiver concerns
  • Suspected bacterial tracheitis, epiglottitis, or other dangerous alternative diagnosis
• ICU admission: Severe croup unresponsive to treatment, impending respiratory failure, need for repeated epinephrine, or intubation [7]
• Specialist consultation: ENT or pediatric pulmonology for recurrent croup, suspected anatomic abnormality, or need for airway intervention [1]

• Follow-up: Primary care within 24–48 hours for moderate cases; sooner if any concerns
• Expected course: Barking cough typically resolves within 48 hours in 60% of children; total illness duration 3–7 days [3]
• Return immediately for:
  • Stridor at rest or worsening breathing difficulty
  • Drooling, inability to swallow
  • Cyanosis or color change
  • Lethargy, decreased responsiveness
  • High fever with toxic appearance
  • Inability to drink fluids
• Parent counseling:
  • Symptoms are typically worst on nights 1–2 and improve thereafter
  • Cool night air may provide temporary relief
  • Keep child calm — crying and agitation worsen stridor
  • Dexamethasone effect lasts ~48–72 hours; additional doses are generally not recommended [7]
  • Recurrent episodes (≥2/year) warrant further evaluation for underlying conditions [1]

1. Croup: Rapid Evidence Review. — Cooke A, Conway S, Griffin L. American Family Physician. 2026.

2. Croup: Diagnosis and Management. — Smith DK, McDermott AJ, Sullivan JF. American Family Physician. 2018.

3. Heliox for Croup in Children. — Moraa I, Sturman N, McGuire TM, van Driel ML. The Cochrane Database of Systematic Reviews. 2021.

4. Acute Upper Airway Obstruction. — Eskander A, de Almeida JR, Irish JC. The New England Journal of Medicine. 2019.

5. Preparation for Pediatric Emergencies in the Office: Technical Report. — Cantrell P, Hoffmann J, Yuknis M, et al. Pediatrics. 2026.

6. Croup. — Bjornson CL, Johnson DW. Lancet. 2008.

7. Croup. — Cherry JD. The New England Journal of Medicine. 2008.

8. Nebulized Epinephrine for Croup in Children. — Bjornson C, Russell K, Vandermeer B, Klassen TP, Johnson DW. The Cochrane Database of Systematic Reviews. 2013.

9. Croup: An Overview. — Zoorob R, Sidani M, Murray J. American Family Physician. 2011.

10. Initial Radiographic Tracheal Ratio in Predicting Clinical Outcomes in Croup in Children. — Yang WC, Hsu YL, Chen CY, et al. Scientific Reports. 2019.

11. Glucocorticoids for Croup in Children. — Gates A, Johnson DW, Klassen TP. JAMA Pediatrics. 2019.

12. Westley Score and Clinical Factors in Predicting the Outcome of Croup in the Pediatric Emergency Department. — Yang WC, Lee J, Chen CY, Chang YJ, Wu HP. Pediatric Pulmonology. 2017.