GA

Croup Notes

Croup

Introduction

  • Respiratory illness: inspiratory stridor, barking cough, hoarseness.
  • Inflammation of larynx and subglottic airway.
  • Mostly mild, but can cause respiratory distress.

Definitions

  • Viral croup: common, 6 months–3 years.
  • Spasmodic croup: abrupt nighttime onset, afebrile, recurrent.
  • Other types: Laryngotracheitis, Laryngotracheobronchitis, Bacterial tracheitis.

Epidemiology

  • Children ≤6 years, peak at 6 months–3 years.
  • More common in boys (M:F ~1.4–2:1).
  • Peak incidence: Fall and early Winter.

Etiology

  • Viral causes (most common):
    • Parainfluenza virus (type 1).
    • RSV, Rhinovirus, Adenovirus.
    • Influenza, SARS-CoV-2.
    • Measles (in outbreaks).
  • Bacterial causes (rare):
    • Mycoplasma pneumoniae.
    • Secondary infection: S. aureus, S. pyogenes, S. pneumoniae.

Pathogenesis

  • Infection spreads to larynx and trachea.
  • Subglottic narrowing: Cricoid cartilage is non-expandable.
  • Inflammation + exudates may lead to severe obstruction.
  • Recurrent/spasmodic croup may involve noninflammatory edema.

Clinical Presentation

  • Usually resolves in 24–72 hours.
  • May have fever, tachypnea, retractions, restlessness.
  • Starts as upper respiratory symptoms → progresses to:
    • Barking cough.
    • Stridor (inspiratory; biphasic in severe cases).
    • Hoarseness.

Evaluation

  • Assess severity (Westley croup score): stridor, retractions, air entry, mental status.
  • Evaluate hydration, rule out other conditions.
  • Maintain calm environment.

Severity Classification

  • Mild: No stridor at rest, mild or no retractions.
  • Moderate: Stridor at rest, mild/moderate retractions.
  • Severe: Marked retractions, agitation, fatigue, poor air entry.
  • Impending respiratory failure: Fatigue, cyanosis, lethargy.

Westley Croup Severity Score

  • Score ≤2: Mild
  • Score 3 to 7: Moderate
  • Score 8 to 11: Severe
  • Score ≥12: Impending respiratory failure

Diagnosis

  • Clinical: Barking cough + stridor in right age group.
  • Imaging only if diagnosis uncertain: “Steeple sign” on neck X-ray = subglottic narrowing.
  • Labs rarely needed unless suspecting secondary infection.

Differential Diagnosis

  • Epiglottitis
  • Bacterial tracheitis
  • Retropharyngeal abscess
  • Foreign body aspiration
  • Anaphylaxis, Airway anomalies, Thermal injury

Recurrent Croup

  • Consider airway abnormalities, GERD, Eosinophilic esophagitis, Atopy.
  • Refer to ENT for scope and imaging.

Management Overview

  • Mild croup: Supportive care + oral dexamethasone.
  • Moderate to severe croup: Dexamethasone (oral/IV/IM), Nebulized epinephrine, Supportive care: hydration, antipyretics, comfort.

Home Treatment (Mild Cases)

  • Encourage fluids, reduce fever.
  • Mist/steam, cold air exposure (optional).
  • Educate caregivers on red flags: stridor at rest, cyanosis, lethargy.

Emergency & Hospital Care

  • ED: Observation 2-4 hours post-epinephrine.
  • Hospital admission if poor response or worsening symptoms.
  • ICU for severe cases requiring frequent epinephrine or respiratory support.

Specific Therapies

  • Glucocorticoids: Dexamethasone preferred, long-acting.
  • Nebulized epinephrine: Rapid relief, short duration.
  • Heliox (select cases): Reduces turbulent airflow.
  • Mist therapy: Comforting, minimal evidence.

Outcomes & Follow-Up

  • Usually resolves in 72 hours.
  • ~5-10% need hospitalization; <1% need ICU.
  • Follow-up within 24 hours if treated in ED.
  • Persistent/recurrent symptoms → ENT referral.