Overview

Croup refers to an infection of the upper airway, which obstructs breathing and causes a characteristic barking cough.

The cough and other symptoms of croup are the result of swelling around the vocal cords (larynx), windpipe (trachea) and bronchial tubes (bronchi). When a cough forces air through this narrowed passage, the swollen vocal cords produce a noise similar to a seal barking. Likewise, taking a breath often produces a high-pitched whistling sound (stridor).

Croup typically occurs in younger children. Croup usually isn't serious and most cases can be treated at home.

Symptoms

Croup often begins as a typical cold. If there is enough inflammation and coughing, a child will develop a loud barking cough. This often is worse at night, and is further aggravated by crying and coughing, as well as anxiety and agitation, setting up a cycle of worsening symptoms. Fever and a hoarse voice are common, too. Your child's breathing may be noisy or labored.

Because children have small airways, they are most susceptible to having more marked symptoms with croup, particularly children younger than 3 years old.

Symptoms of croup usually last for three to five days.

When to see a doctor

Approximately 5 percent of children seen in the emergency department for croup require hospitalization. You should seek immediate medical attention if your child:

  • Makes noisy, high-pitched breathing sounds (stridor) both when inhaling and exhaling
  • Begins drooling or has difficulty swallowing
  • Seems anxious and agitated or fatigued and listless
  • Breathes at a faster rate than usual
  • Struggles to breathe
  • Develops blue or grayish skin around the nose, mouth or fingernails (cyanosis)

Causes

Croup is usually caused by a virus infection, most often a parainfluenza virus.

Your child may contract a virus by breathing infected respiratory droplets coughed or sneezed into the air. Virus particles in these droplets may also survive on toys and other surfaces. If your child touches a contaminated surface and then touches his or her eyes, nose or mouth, an infection may follow.

Risk factors

Most at risk of getting croup are children between 6 months and 3 years of age. The peak incidence of the condition is around 24 months of age.

Complications

Most cases of croup are mild. In a small percentage of cases, the airway swells enough to interfere with breathing.

Prevention

To prevent croup, take the same steps you use to prevent colds and flu. Frequent hand-washing is the most important. Also keep your child away from anyone who's sick, and encourage your child to cough or sneeze into his or her elbow.

To stave off more-serious infections, keep your child's vaccinations current. The diphtheria and Haemophilus influenza type b vaccines offer protection from some of the rarest — but most dangerous — upper airway infections. There isn't a vaccine yet that protects against parainfluenza viruses.