Viral croup; Laryngotracheobronchitis - acute; Spasmodic croup
Causes, incidence, and risk factors
Viral croup is the most common. Other possible causes include bacteria, allergies, and inhaled irritants. Acid reflux from the stomach can trigger croup.
Croup is usually (75% of the time) caused by parainfluenza viruses, but RSV, measles, adenovirus, and influenza can all cause croup.
Before the era of immunizations and antibiotics, croup was a dreaded and deadly disease, usually caused by the diphtheria bacteria. Today, most cases of croup are mild. Nevertheless, it can still be dangerous.
Croup tends to appear in children between 3 months and 5 years old, but it can happen at any age. Some children are prone to croup and may get it several times.
In the northern hemisphere, it is most common between October and March, but can occur at any time of the year.
In severe cases of croup, there may also be a bacterial superinfection of the upper airway. This condition is called bacterial tracheitis and requires hospitalization and intravenous antibiotics. If the epiglottis becomes infected, the entire windpipe can swell shut, a potentially fatal condition called
Review Date: 05/13/2010
Reviewed By: Linda J. Vorvick, MD, Medical Director, MEDEX Northwest Division of Physician Assistant Studies, University of Washington, School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.