What are the symptoms of croup (acute laryngotracheobronchitis)?

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From the Guidelines

Croup is characterized by a distinctive barking cough, hoarseness, and stridor, typically beginning with cold-like signs such as runny nose and fever, then progressing to the barking cough, especially at night, as noted in the context of parainfluenza virus infections 1. The symptoms of croup often include:

  • A barking cough
  • Hoarseness
  • Stridor (a high-pitched, harsh sound during breathing in)
  • Cold-like signs such as runny nose and fever
  • Difficulty breathing
  • Retractions (visible pulling in of the chest)
  • Increased respiratory rate These symptoms typically worsen at night and when the child is upset or crying. According to the study by the Infectious Diseases Society of America and the American Society for Microbiology 1, parainfluenza viruses are a major cause of croup, with types 1 and 2 most commonly associated with croup syndrome. The diagnosis of croup can be supported by diagnostic tests such as culture and nucleic acid amplification tests (NAATs) on respiratory secretions or nasopharyngeal swabs 1. Management of croup typically involves cool mist humidification, hydration, and comfort measures for mild cases, while moderate to severe cases may require a single dose of oral dexamethasone to reduce inflammation in the airways 1.

From the Research

Symptoms of Croup

  • Croup is characterized by the abrupt onset of a barking cough, inspiratory stridor, hoarseness, and respiratory distress due to upper airway obstruction 2
  • Symptoms typically include a low-grade fever, barking cough, and inspiratory stridor, often preceded by an upper respiratory infection 3
  • Croup can lead to signs of upper airway obstruction, and must be differentiated from acute epiglottitis, bacterial tracheitis, or an inhaled foreign body 2
  • The condition usually affects children between the ages of 6 months and 3 years, with 75% of infections caused by parainfluenza virus 2

Severity of Symptoms

  • Mild croup is characterized by the presence of stridor without intercostal retractions, whereas moderate-to-severe croup is accompanied by increased work of breathing 4
  • Severe upper airway obstruction can, rarely, lead to respiratory failure and arrest 2
  • Symptoms usually resolve within 48 hours, but some cases can present with significant pathology and may not improve as rapidly as those with typical croup 5

Diagnosis and Treatment

  • Diagnosis is made on clinical grounds with no specific confirmatory test, but pathogen testing may be indicated in cases of "COVID-19 croup" 3, 5
  • Treatment typically involves corticosteroids, such as dexamethasone, which can decrease the intensity of viral croup symptoms irrespective of their severity on presentation to the emergency department 4
  • Nebulized epinephrine and heliox therapy may also be used in cases of moderate-to-severe croup or COVID-19 croup 3, 4, 5

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Croup.

BMJ clinical evidence, 2014

Research

Croup.

The Journal of family practice, 1993

Research

Viral croup: diagnosis and a treatment algorithm.

Pediatric pulmonology, 2014

Research

Pediatric croup with COVID-19.

The American journal of emergency medicine, 2021

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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