Croup is a viral illness with inflammation of the upper airway. It is also known as acute viral laryngo-tracheo-bronchitis.


  • Viral prodrome (1-2 days corryzal symptoms).
  • Harsh barking cough.
  • Hoarse voice and stridor.
  • Fever <38°.
  • Stridor worse on crying and worse at night.


  • Tachypnoea.
  • Tachycardia.
  • Sternal recession.
  • Tracheal tug.
  • Cyanosis on crying.


  • Continuous harsh sound.
  • Caused by obstruction in the larynx and trachea.
  • Predominantly an inspiratory .
  • Expiratory component may be present
    ? subglottic lesion.
  • Higher incidence in children than in adults (anatomical differences).

Differential diagnosis of stridor

  • Acute laryngo-tracheo-bronchitis(croup).
  • Acute epiglottitis.
  • Bacterial tracheitis.
  • Foreign body.
  • Acute angioneurotic oedema(anaphylaxis).
  • Diphtheria.
  • Expanding mediastinal mass.
  • Tetany.
  • Peritonsillar or retropharyngeal abscess.

Croup management

Mild croup

  • General supportive measures, gentle handling and reassurance.
  • Oral Dexamethasone (150 microgrammes /kg).
  • Hydration should be assured by allowing the parents to feed the child.
  • Investigation should be kept to a minimum.
  • No lateral neck radiographs.

Moderate/severe croup

  • Consider resusc. room.
  • Oxygen if any hypoxia.
  • Oral Dexamethasone (150 microgrammes /kg) (nebulised budesonide 2mg if not tolerating po Dex).
  • Nebulised Adrenaline[Epinephrine] (5mls of 1 in 1,000) with cardiac monitor.
  • If nebulised Adrenaline has been given, please obtain IV access and request paediatric admission.

Indicators of increasing severity (needs admission):

  • Increasing respiratory rate.
  • Increasing stridor.
  • ↓ air entry on auscultation.
  • Cyanosis at rest with O2 sats. <95% in air.
  • Δ level of consciousness.

At risk

Children with:

  • pre-existing narrowing of the upper airways (eg. subglottic stenosis congenital or 2° to neonatal ventilation) or
  • children with Down Syndrome

are prone to more severe croup and admission should be considered even with mild symptoms.

Content Dr Íomhar O' Sullivan 01/04/2004.  Reviewed by Dr Chris Luke 20/01/2005 & by Dr ÍOS 31/07/2007, 1/03/19.