What are the symptoms of croup?

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Symptoms of Croup

Croup is characterized by a sudden onset of a distinctive barking cough, inspiratory stridor, hoarse voice, and respiratory distress resulting from upper airway obstruction. 1, 2

Primary Symptoms

  • Barking cough: Often described as "seal-like" or "dog-like" bark, this is the most distinctive symptom 3
  • Stridor: Harsh, high-pitched sound during inspiration, may worsen with agitation or crying 2
  • Hoarse voice: Changes in vocal quality due to laryngeal inflammation 3
  • Respiratory distress: Varying degrees of breathing difficulty 2

Progression and Associated Symptoms

Croup typically follows a predictable pattern:

  • Initial phase: Symptoms often begin like an upper respiratory infection with:
    • Low-grade fever
    • Coryza (runny nose)
    • Mild cough 3
  • Progressive phase:
    • Development of the characteristic barking cough
    • Inspiratory stridor (initially only when agitated, later at rest)
    • Increased work of breathing 1

Severity Assessment

Symptoms can be classified by severity:

Mild Croup

  • Barking cough
  • No audible stridor at rest
  • Minimal or no respiratory distress 2

Moderate Croup

  • Barking cough
  • Audible stridor at rest
  • Mild to moderate respiratory distress with retractions 2

Severe Croup

  • Prominent inspiratory and expiratory stridor
  • Significant respiratory distress with marked retractions
  • Agitation or lethargy
  • Decreased air entry
  • Possible cyanosis or oxygen saturation <92% 2

Timing and Duration

  • Symptoms typically worsen at night
  • Most cases show improvement within 48 hours
  • The barking cough usually resolves within 2 days 3

Distinguishing Features from Other Conditions

It's important to differentiate croup from other serious conditions:

  • Unlike epiglottitis: Croup has a gradual onset rather than rapid progression, and patients typically don't have dysphagia or drooling 1
  • Unlike foreign body aspiration: Croup has a viral prodrome and fever, rather than sudden onset without fever 1
  • Unlike bacterial tracheitis: Croup typically has milder symptoms and responds to steroids 3

Common Pitfalls in Symptom Recognition

  • Mistaking croup for asthma or bronchiolitis (croup affects upper airway, not lower)
  • Failing to recognize progression from mild to severe symptoms
  • Confusing croup with other causes of stridor such as epiglottitis (which presents with more toxic appearance, drooling, and inability to swallow) 2

Croup is most common in children 6 months to 6 years of age, with peak incidence in the second year of life, and typically presents in late fall or early winter 4, 3. While most cases are mild and self-limiting, recognition of progressive symptoms is crucial as severe cases may require immediate medical intervention.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Guideline

Croup Management Guidelines

Praxis Medical Insights: Practical Summaries of Clinical Guidelines, 2025

Research

Croup: an overview.

American family physician, 2011

Research

Croup.

The Journal of family practice, 1993

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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