Croup

1. History

• Barking/seal-like cough — the hallmark symptom; abrupt onset, classically worse at night [1][4]
• Preceding 1–3 day URI prodrome: rhinorrhea, nasal congestion, low-grade fever [5-6]
• Timing: symptoms peak on days 2–3, barking cough resolves within 48 hours in ~60% [5]
• Severity characterization: stridor at rest vs. only with agitation, degree of respiratory distress, ability to feed/drink
• Hoarseness or voice change
• Ask about fever (may reach 40°C, but high fever with toxic appearance suggests alternative diagnosis) [7]
• Important negatives: no drooling, no dysphagia, no sudden onset without prodrome, no foreign body ingestion history

2. Alarm Features

• Stridor at rest (moderate-severe croup)
• Marked chest wall retractions (suprasternal, intercostal, subcostal)
• Cyanosis or SpO₂ <92%
• Lethargy, altered consciousness, or agitation disproportionate to respiratory effort
• Toxic appearance — suggests bacterial tracheitis, epiglottitis, or abscess [2][7]
• Drooling, refusal to swallow, tripoding/sniffing position — classic for epiglottitis [7-8]
• No response to standard dexamethasone + nebulized epinephrine — consider bacterial tracheitis [7]
• Rapid progression or biphasic stridor
• Age <6 months or >6 years (atypical age → consider anatomic abnormality or alternative diagnosis) [2]

3. Medications

• First-line: Dexamethasone — single oral dose 0.6 mg/kg (max 12 mg), regardless of severity. Prednisolone is an acceptable alternative [2]
• Moderate-severe: Nebulized racemic epinephrine — 0.5 mL of 2.25% in 4.5 mL NS; or L-epinephrine 5 mL of 1:1000 [4][7]
• Antibiotics are not indicated for uncomplicated croup [5]
• Avoid sedatives (may worsen airway obstruction)
• Avoid cough suppressants — no role in croup management
• Humidified mist therapy has no proven benefit [2][6]
• Heliox: limited evidence, may be considered in severe cases as a bridge while awaiting steroid effect [5]

4. Diet

• Encourage clear fluids to maintain hydration
• Avoid forcing oral intake in a child with significant respiratory distress (aspiration risk)
• Cool fluids may provide mild symptomatic comfort
• No specific dietary triggers or restrictions

5. Review of Systems

• Respiratory: cough character (barking vs. productive), stridor (inspiratory vs. biphasic), work of breathing, apneic episodes
• ENT: voice changes, drooling, dysphagia, sore throat
• Constitutional: fever, irritability, lethargy, poor feeding
• GI: vomiting (from coughing paroxysms), ability to tolerate fluids
• Allergic/Atopic: history of eczema, asthma, allergic rhinitis (associated with recurrent croup) [2]
• GI/Reflux: GERD symptoms (associated with recurrent croup) [2]

6. Collateral History and Family History

• Sick contacts, daycare/school exposure
• Immunization status — particularly Hib vaccine (epiglottitis risk if under-immunized) [2][9]
• Prior episodes of croup (≥2 episodes → evaluate for anatomic abnormality or GERD) [2]
• Family history of asthma, atopy, or subglottic stenosis
• History of prior intubation or airway surgery (subglottic stenosis risk)
• Birth history: prematurity, neonatal intubation

7. Risk Factors

• Age 6 months to 3 years (peak incidence in second year of life) [5][10]
• Male sex (male:female ratio ~1.5–2:1), possibly related to impaired antiviral immunity [2][5]
• Fall/winter seasonality — peak October–November, coinciding with parainfluenza type 1 epidemics [2][10-11]
• Daycare attendance / viral exposure
• Atopy, asthma, or allergic conditions (risk factor for recurrent croup) [2][5]
• GERD [2]
• Underlying airway abnormality (subglottic stenosis, tracheomalacia) [2]
• Under-immunization (risk for diphtheria, measles-related croup in unvaccinated populations) [5]

8. Differential Diagnosis

• Bacterial tracheitis — toxic-appearing child, worsening despite standard croup therapy, thick tracheal secretions; most common pathogen is S. aureus [7]
• Epiglottitis — sudden high fever, drooling, dysphagia, tripoding, muffled voice, absence of barking cough; consider in under-immunized children [2][7-8]
• Foreign body aspiration — sudden onset without prodrome or fever, no barking cough, possible witnessed choking event [4][7]
• Retropharyngeal/peritonsillar abscess — dysphagia, drooling, neck stiffness, unilateral cervical adenopathy [7]
• Angioedema — rapid onset, possible urticaria, history of allergy or ACE inhibitor use [4][7]
• Spasmodic croup — recurrent episodes without viral prodrome, often atopic child, responds well to cool air [4]
• Laryngeal diphtheria — gradual onset, pharyngeal membrane, inadequate immunization [7]
• Subglottic stenosis or hemangioma — consider in recurrent or atypical presentations, especially age <6 months

Key differentiating feature: coughing predicts croup (sensitivity 1.00, specificity 0.98), while drooling predicts epiglottitis (sensitivity 0.79, specificity 0.94). [8]

9. Past Medical History

• Prior episodes of croup (recurrent croup = ≥2 episodes/year) [2]
• History of intubation or airway instrumentation
• Known subglottic stenosis or airway anomaly
• Prematurity
• Asthma or reactive airway disease
• GERD
• Immunodeficiency
• Congenital heart disease (may worsen with respiratory distress)

10. Physical Exam

• Vital signs: tachypnea, tachycardia (proportional to distress), fever (usually low-grade), SpO₂ (may be normal in mild-moderate cases)
• General: assess degree of distress, level of consciousness, position of comfort
• Airway: inspiratory stridor (at rest = moderate-severe; with agitation only = mild) [4][6]
• Chest wall: intercostal, subcostal, suprasternal retractions [5]
• Lungs: air entry (decreased in severe cases), absence of wheezing (wheezing/crackles suggest lower airway involvement → laryngotracheobronchitis) [4]
• Oropharynx: examine gently — no drooling, no pharyngeal membrane, no peritonsillar bulging
• Neck: no cervical lymphadenopathy or neck stiffness (if present → consider abscess)
• Skin: no urticaria or angioedema
• Concerning findings: cyanosis, lethargy, markedly diminished air entry, biphasic stridor

Pearl: Minimize agitation during examination — crying worsens dynamic airway obstruction. [5]

11. Lab Studies

• Labs are typically unnecessary for the diagnosis of croup [2-3]
• Viral cultures and rapid antigen testing have minimal impact on management and are not routinely recommended [3][7]
• If bacterial tracheitis or laryngotracheobronchopneumonia is suspected: CBC with differential (elevated or low WBC with bandemia), blood cultures [4]
• Procalcitonin and NLR may correlate with severity in research settings but are not standard clinical practice [12]
• Rapid influenza testing may be considered in appropriate season if influenza-specific treatment would be initiated [4]

12. Imaging

• Imaging is not routinely indicated for classic croup presentations [2][7]
• AP neck radiograph: classic "steeple sign" (subglottic narrowing) — supportive but not diagnostic; sensitivity is limited
• Lateral neck radiograph: useful if epiglottitis suspected (thickened epiglottis, "thumbprint sign") or retropharyngeal abscess (widened prevertebral soft tissue) [4][7]
• Bacterial tracheitis on imaging: ragged tracheal contour or intraluminal membrane [7]
• Important: radiographs can be normal even in epiglottitis or bacterial tracheitis [7]
• If imaging is obtained, the child must be closely monitored by skilled personnel with airway management equipment [7]
• CT neck with contrast: reserved for suspected deep space neck infections (retropharyngeal/peritonsillar abscess)

13. Special Tests

Westley Croup Score — the most widely used severity scoring system: [4-5]

• Mild: Westley score ≤2 (barking cough, no stridor at rest)
• Moderate: Westley score 3–5 (stridor at rest, mild retractions)
• Severe: Westley score ≥6 (stridor at rest, marked retractions, decreased air entry, distress) [5][13]

Patients with initial Westley score <2 can generally be safely treated at home; those with score ≥5 are more likely to require hospitalization. [13]

• Laryngoscopy/bronchoscopy: reserved for atypical presentations, recurrent croup in children <3 years, or suspected anatomic abnormality [2]
• Triple endoscopy (laryngoscopy, bronchoscopy, esophagoscopy): for recurrent croup with high suspicion for airway abnormality [2]

14. ECG

• ECG is not routinely indicated in croup
• Consider cardiac monitoring if multiple doses of nebulized epinephrine are administered — one case report of ventricular tachycardia and myocardial infarction in a child receiving 3 doses within 1 hour [6-7]
• Single-dose nebulized epinephrine has not been associated with clinically significant tachycardia or blood pressure changes [7]
• Monitor for tachycardia and pallor as mild side effects of epinephrine [7]

15. Assessment

Croup is a clinical diagnosis based on the triad of barking cough, inspiratory stridor, and hoarseness, typically preceded by a URI prodrome in a child aged 6 months to 3 years. [7] Approximately 85% of cases are mild, with <1% classified as severe. [4] The illness is self-limiting, with barking cough resolving within 48 hours in 60% of children. [5] Only 1–8% require hospitalization, and <3% of admitted patients require intubation. [14]

Atypical features that should raise concern: age outside the typical range, toxic appearance, failure to respond to standard therapy, drooling, absence of cough, or recurrent episodes. [2][4]

16. Treatment Plan

Mild croup (Westley ≤2)

• Dexamethasone 0.6 mg/kg PO × 1 dose (max 12 mg) [2][4]
• Supportive care: comfort measures, cool air exposure (<50°F/10°C for 30 min may reduce symptoms when combined with dexamethasone) [2]
• Reassess in 30 minutes [2]

Moderate croup (Westley 3–5)

• Dexamethasone 0.6 mg/kg PO × 1 dose [2]
• Nebulized racemic epinephrine 0.5 mL of 2.25% in 4.5 mL NS (or L-epinephrine 5 mL of 1:1000) [4][7]
• Observe 2–4 hours post-epinephrine for symptom recurrence [2][7]
• Reassess; if improved and stable → discharge with precautions

Severe croup (Westley ≥6)

• Nebulized epinephrine (may repeat as needed) + dexamethasone [4][15]
• Supplemental oxygen if SpO₂ <92%
• Minimize agitation — keep child in parent's lap
• Continuous cardiorespiratory monitoring and pulse oximetry [7]
• If no response: consider heliox as bridge therapy, prepare for advanced airway management [5]
• If bacterial superinfection suspected: IV antibiotics (vancomycin + cefotaxime) and consider intubation [4]

Key pharmacologic pearl: Corticosteroids take ~30 minutes to begin working; epinephrine works within 10–30 minutes but effect wears off by 2 hours. [5-6] Symptoms return to baseline (not worse) as epinephrine wears off. [7]

17. Disposition

18. Follow Up / Return Precautions

• Follow-up: PCP within 24–48 hours if discharged from ED, sooner if symptoms persist
• Expected course: barking cough typically resolves within 2–3 days; total illness duration 3–7 days [5]
• Up to 5% of children discharged from the ED return, underscoring the importance of appropriate steroid treatment and clear return precautions [2]