Clinical Evidence Handbook

A Publication of BMJ Publishing Group

Croup

 

Am Fam Physician. 2016 Sep 15;94(6):476-478.

Author disclosure: David Wyatt Johnson is the author of references cited in this review.

Croup leads to signs of upper airway obstruction and must be differentiated from acute epiglottitis, bacterial tracheitis, and an inhaled foreign body.

  • Croup affects about 3% of children per year, usually those between the ages of six months and three years, and 75% of infections are caused by parainfluenza virus.

  • Symptoms usually resolve within 48 hours, but severe upper airway obstruction can rarely lead to respiratory failure and arrest.

  • Oxygen is standard treatment in children with respiratory distress.

    A single oral dose of dexamethasone improves symptoms in children with mild croup, compared with placebo.

  • Although humidification is often used in children with mild to moderate croup, we found no evidence from randomized controlled trials to support its use in clinical practice.

    In children with moderate to severe croup, intramuscular or oral dexamethasone, nebulized adrenaline (epinephrine), and nebulized budesonide reduce symptoms compared with placebo.

  • Oral dexamethasone is as effective as nebulized budesonide at reducing symptoms, and is less distressing for the child.

  • A dexamethasone dose of 0.15 mg per kg may be as effective as a dose of 0.6 mg per kg. Adding nebulized budesonide to oral dexamethasone does not seem to improve efficacy compared with either drug alone.

  • We do not know whether heliox (helium-oxygen mixture) or humidification is beneficial in children with moderate to severe croup.

View/Print Table

Clinical Questions

What are the effects of treatments (dexamethasone or humidification) in children with mild croup?

Beneficial

Dexamethasone (oral single dose; reduced need for further medical attention for ongoing symptoms compared with placebo)

Unlikely to be beneficial

Humidification*

What are the effects of treatments in children with moderate to severe croup?

Beneficial

Budesonide, nebulized (compared with placebo)

Dexamethasone, intramuscular or oral (compared with placebo)

Likely to be beneficial

Adrenaline (epinephrine), nebulized (compared with placebo)

Dexamethasone, intramuscular (improves croup scores compared with nebulized budesonide)

Dexamethasone, oral (compared with nebulized budesonide)*

Unknown effectiveness

Dexamethasone, oral, higher dose vs. lower dose (unclear which dose is most effective)

Dexamethasone, intramuscular vs. dexamethasone, oral (unclear which route of administration is most effective)

Dexamethasone, oral (compared with oral prednisolone)

Heliox (helium-oxygen mixture)

L-adrenaline (epinephrine) compared with racemic adrenaline

Unlikely to be beneficial

Dexamethasone, oral, plus budesonide, nebulized, vs. either drug alone

Humidification


*—Based on consensus.

Clinical Questions

What are the effects of treatments (dexamethasone or humidification) in children with mild croup?

Beneficial

Dexamethasone (oral single dose; reduced need for further medical attention for ongoing symptoms compared with placebo)

Unlikely to be beneficial

Humidification*

What are the effects of treatments in children with moderate to severe croup?

Beneficial

Budesonide, nebulized (compared with placebo)

Dexamethasone, intramuscular or oral (compared with placebo)

Likely to be beneficial

Adrenaline (epinephrine), nebulized (compared with placebo)

Dexamethasone, intramuscular (improves croup scores compared with nebulized budesonide)

Dexamethasone, oral (compared with nebulized budesonide)*

Unknown effectiveness

Dexamethasone, oral, higher dose vs. lower dose (unclear which dose is most effective)

Dexamethasone, intramuscular vs. dexamethasone, oral (unclear which route of administration is most effective)

Dexamethasone, oral (compared with oral prednisolone)

Heliox (helium-oxygen mixture)

L-adrenaline (epinephrine) compared with racemic adrenaline

Unlikely to be beneficial

Dexamethasone, oral, plus budesonide, nebulized, vs. either drug alone

Humidification


*—Based on consensus.

Definition

Croup is characterized by the abrupt onset, most commonly at night, of a barking cough, inspiratory stridor, hoarseness, and respiratory distress due to upper airway obstruction. Croup symptoms are often preceded by symptoms like those of an upper respiratory tract infection. The most important diagnoses to differentiate from croup include bacterial tracheitis, epiglottitis, and the

Author disclosure: David Wyatt Johnson is the author of references cited in this review.

This is one in a series of chapters excerpted from the Clinical Evidence Handbook, published by the BMJ Publishing Group, London, U.K. The medical information contained herein is the most accurate available at the date of publication. More updated and comprehensive information on this topic may be available in future print editions of the Clinical Evidence Handbook, as well as online at http://www.clinicalevidence.bmj.com (subscription required).

This series is coordinated by Kenny Lin, MD, MPH, Associate Deputy Editor for AFP Online.

A collection of Clinical Evidence Handbook published in AFP is available at http://www.aafp.org/afp/bmj.


 

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