Croup

Lore & Background

Croup is typically diagnosed based on signs and symptoms after ruling out more severe causes such as epiglottitis or an airway foreign body. The infection leads to swelling of the larynx, trachea, and large bronchi due to infiltration of white blood cells, producing airway obstruction and the characteristic turbulent airflow known as stridor. The most commonly used system for classifying severity is the Westley score, which ranges from 0 to 17, with mild cases scoring ≤2 and severe cases scoring ≥12.

Reader's Guide

Croup is a relatively common condition that affects about 15% of children at some point, most often between six months and five years of age. It is usually caused by viral infections, most commonly parainfluenza virus, and is typically mild, with most cases treated at home with supportive care. Corticosteroids, such as dexamethasone, are routinely used for moderate to severe cases, and inhaled epinephrine may be used in severe cases. Hospitalization is required in one to five percent of cases. Before vaccination, croup was frequently caused by diphtheria and was often fatal; this cause is now very rare in the Western world due to the diphtheria vaccine. Many cases are preventable by immunization for influenza and diphtheria.

Did You Know?

• Croup is characterized by a barking cough often described as resembling the call of a sea lion.
• The steeple sign, a narrowing of the trachea seen on X-ray, is suggestive of croup but is absent in half of cases.
• Croup is slightly more common in males than females.
• Less than 0.2% of children with croup require endotracheal intubation.