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:
1. History
- 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
2. Alarm Features
- 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
3. Medications
- 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]
4. Diet
- 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
5. Review of Systems
- 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)
6. Collateral History and Family History
- 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
7. Risk Factors
- 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]
8. Differential Diagnosis
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]
9. Past Medical History
- 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)
10. Physical Exam
- 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]
11. Lab Studies
- 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]
12. Imaging
- 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
13. Special Tests
- 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]
14. ECG
- 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
15. Assessment
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]
16. Treatment Plan
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]
17. Disposition
- 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]
18. Follow Up / Return Precautions
- 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]
References
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.