Definition: Respiratory illness defined by inspiratory stridor, cough and hoarseness in the setting of viral illness.
- Croup may be caused by a number of viruses.
- Common Causes: parainfluenza virus, influenza virus, adenovirus and respiratory syncytial virus.
- Rare Causes: human metapneumovirus, measles, varicella, human coronavirus or HSV-1.
- Age 6 months to 36 months most common
- Can be seen in 3 month up to preschool age, uncommon >6years
- Peak mid fall to early winter
- Peak time to visit ED 10pm-4am
- Intubation may be required for severe respiratory distress
- Bacterial tracheitis can cause rapid deterioration
- Also called bacterial laryngotracheobronchitis
- Bacterial super-infection that can mimic viral croup
- Common pathogens: staph aureus, strep pneumo, group A strep, Moraxella
- Rarely: Pseudomonas, Haemophilus parainfluenzae, Klebsiella, E.Coli
- Pneumonia is a rare complication
- Life-threatening mimics of croup
- Infectious: Acute Epiglottitis and Bacterial Tracheitis
- Mechanical: Inhaled Foreign body and Allergic reaction/anaphylaxis
- Other less emergent cause of stridor and/or barky cough:
- Infectious: Peritonsillar/retropharyngeal abscess, Ludwig’s angina, laryngeal diphtheria and cervical adenitis
- Mechanical: Upper airway injury, Congenital upper airway anomalies, neck/c-spine trauma, smoke inhalation, neck masses, laryngomalacia
- 1-3 days of nonspecific upper airway obstruction
- Barking, seal-like cough
- Low grade fever
- Nighttime symptoms
- Stridor at rest or only with agitation/coughing
- Biphasic stridor indicates high grade obstruction
- Respiratory distress
- Assess the patients:
- Air entry
- Skin color
- Hoarse voice
Westley Croup Score
|CYANOSIS IN ROOM AIR||Normal||0|
|TOTAL SCORE: Mild 1-2, Moderate 3-8 Severe >8|
The Westley croup score is mostly used for research purposes but may help guide clinical management and disposition if used at presentation
- Supportive maneuvers include avoidance of agitating the child most importantly.
- Humidified air has limited evidence for efficacy (Moore 2006)
- Corticosteroids: Corticosteroids decrease airway inflammation and edema
- HeliOx: Heliox is a combination of helium and oxygen
- 2 concentrations available, 70% helium 30% oxygen and 80% helium and 20% oxygen. T
- Lower density of the mixture results in decreased airway turbulence
- Heliox cannot be used in in patients requiring more than 30% oxygen
- Heliox may be considered in the patient with severe croup to possibly forestall intubation
- Patients without stridor at rest or respiratory distress can generally be discharged from emergency department.
- Patients treated with epinephrine should be observed for 2-4 hours for reemergence of symptoms as the medication wears off.
- The patient may return to pretreatment symptoms but rarely worsen.
- Most patients who receive 2 or more doses of epinephrine in the ED do not have any significant interventions in the inpatient setting (Rudinsky 2015)
- Some patients with significant airway edema will require intubation. These patients will need ICU level care.
- In the child with prolonged symptoms who is highly febrile with deteriorating respiratory status the diagnosis of bacterial tracheitis should be considered.
Take Home Points
- Croup usually has a benign course, but can lead to life threatening respiratory compromise
- High fever, toxic appearance and poor response to therapy suggests bacterial tracheitis or other diagnosis
- Children with persistent stridor after treatment with racemic epinephrine and dexamethasone require admission
Bjornson CL et al. A randomized trial of a single dose of oral dexamethasone for mild croup. N Engl J Med. 2004 Sep 23;351(13):1306-13. PMID: 15385657
Bjornson C et al. Nebulized epinephrine for croup in children. Cochrane Database Syst Rev. 2013 Oct 10;(10). PMID: 24114291
Cherry, JD Clinical Practice. Croup. N Engl J Med. 2008 Jan 24;358(4):384-91 PMID: 18216359
Moore M, Little P. Humidified air inhalation for treating croup. Cochrane Database Syst Rev. 2006 Jul 19;(3). PMID: 16855994
Rudinsky SL et al. Inpatient Treatment after Multi-Dose Racemic Epinephrine for Croup in the Emergency Department. J Emerg Med. 2015 Oct;49(4):408-14. PMID: 26242923
Sparrow A, Geelhoed G. Prednisolone versus Dexamethasone in croup: a randomized equivalence trial. Arch Dis Child. 2006 Jul;91(7):590-3. PMID: 16624882
Toward Optimized Practice (TOP) Working Group for Croup. 2008 January. Diagnosis and management of croup. Edmonton, AB: Toward Optimized Practice. Available from: https://www.topalbertadoctors.org
Waisman Y et al. Prospective randomized double-blind study comparing L-epinephrine and racemic epinephrine aerosols in the treatment of laryngotracheitis (croup). Pediatrics. 1992:89(2):302-6. PMID: 1734400