Encyclopedia / C / Croup



Croup, also known as laryngotracheitis, is an inflammation and narrowing of the larynx (voice box) and the trachea (windpipe) caused by an infection.


Croup generally occurs in children aged 3 months to 6 years. However, croup over the age of 3 years is uncommon because the windpipe is larger, therefore any swelling is less likely to get in the way of breathing. Most children have only one episode of croup, but a few children have multiple episodes. Croup can occur at any time of year, although most outbreaks are during the winter months.

An infection causes a swelling and outpouring of secretions in the voice box, the windpipe and the larger airways going to the lungs. The air passages of young children are made narrower because of the swelling. This swelling is further aggravated by the secretions, which may become dried out and caked. This combination of swelling and thickened, dried secretions makes it extremely difficult to breathe and croup develops. There may also be considerable spasms of the airway passages, further complicating the condition.


There are four different types of croup:

1. Laryngotracheobronchitis (commonly known as viral croup)

2. Spasmodic laryngitis (commonly known as spasmodic croup)

3. Infectious laryngitis

4. Epiglottitis (also known as supraglottis)

Laryngotracheobronchitis (viral croup) is the most common type of croup and usually occurs in children ages 3 months to 5 years. Viral croup is caused by viruses such as parainfluenza type 1 and 3, influenza A, adenovirus, respiratory syncytial virus, echovirus and mycoplasma. Viral croup comes on gradually, usually after flu or cold symptoms have occurred.

Spasmodic laryngitis (spasmodic croup) usually occurs in children ages 1 to 3 years. Spasmodic croup is caused by an upper respiratory infection, allergy or psychological factors. Spasmodic croup comes on suddenly and usually occurs at night.

Infectious laryngitis can occur in all age groups and is usually caused by the influenza, a virus, rhinovirus or adenovirus, and affects the vocal cords.

Conditions that may be confused with Croup

Epiglottitis can occur in children ages 2 to 6 years. This type of croup is rare but very serious, and sometimes fatal, and is caused by a bacterium called Hemophilus influenza type b (Hib). Unlike the other types of croup that involve the swelling of the windpipe and trachea, epiglottitis involves the sudden swelling and inflammation of the epiglottis (the flap of cartilage at the back of the tongue that closes off the windpipe during swallowing). The swollen epiglottis obstructs breathing and if left untreated could lead to death by suffocation (lack of oxygen). There is a vaccine, called the Hib vaccine, that protects against the common cause of epiglottitis - Hemophilus influenza type b bacteria. Symptoms suggesting this illness include painful swallowing or refusal to eat, drooling, sudden onset with no other upper respiratory symptoms such as runny nose and cough, and high fever. If you are concerned about epiglottitis in your child, call your physician immediately and plan to go to the nearest emergency room. See discussion below with regard to emergency room evaluation of epiglottitis.


The general symptoms of croup include:

  • harsh, high-pitched respiratory sound called a stridor
  • a brassy, barking cough
  • a hoarse cry
  • difficulty breathing

In addition to the above stated symptoms,a child with viral croup may also experience:

  • low-grade fever
  • rattling sounds while exhaling
  • scattered crackles in the chest

A child with spasmodic croup may also experience:

  • runny nose
  • noisy inhalation
  • rapid pulse
  • clammy skin
  • labored breathing with retractions (chest sinking in)

A child with infectious laryngitis may also experience:

  • sore throat
  • loss of voice

Note: The symptoms of croup fluctuate rapidly and unpredictably. From hour to hour, a child's breathing may be normal and then grow loud and uncomfortable.

A child with epiglottitis may experience the following symptoms:

  • fever
  • serious difficulty in breathing
  • stridor
  • drooling
  • painful swallowing
  • restlessness (trying to find a more comfortable position that will make it easier to breathe)
  • rapid heart rate
  • semiconscious
  • bluish coloring around the lips and mouth
  • unable to bend the neck forward

If the child is experiencing the symptoms of epiglottitis, contact the doctor or 911 immediately.


Diagnosis of croup is based on the medical history of the child, the symptoms (especially the evidence of the barking cough) and a physical examination of the throat. Additionally the doctor may take a throat culture to determine if the infection is viral or bacterial, as well as a neck x-ray to check for foreign obstructions in the throat, upper airway narrowing and swelling and/or a swollen epiglottis.


For most children with viral croup, spasmodic croup or infectious laryngitis the following simple measures are all that is necessary to alleviate the symptoms:

  • Administer mist therapy which involves sitting in a steam-filled bathroom, with the window open and the door closed. Turn on the hot water in the shower or tub and let the room fill up with steam. Sit with the child in the room, with the water still running, for 10 minutes.
  • Bundle the child up in warm clothes and take them outside in the cool night air for 10-15 minutes.
  • Use a cool mist vaporizer or humidifier in the child's room
  • Give the child plenty of clear fluids such as apple juice, water or popsicles to suck on
  • Treat the fever with acetaminophen (Tylenol or Tempra)
  • Avoid smoke or smoke-filled rooms.
  • Keep the child calm and reassured

Note: be sure to check on the child at least every two hours to be certain that breathing has not become labored. If the child continues to experience stridor, retractions around the neck and ribs or severe breathing difficulty, seek prompt medical care.

Treatment of croup in the doctor's office or hospital depends on the severity of the croup and may include:

  • administration of oxygen
  • mist therapy
  • administering a nebulized (inhaled) saline solution
  • administering nebulized racemic epinephrine
  • administering an oral or intramuscular corticosteroid called dexamethasone (Decadron, Hexadrol)
  • administering a nebulized synthetic glucocorticoid called budesonide (still experimental)

Evaluation and Treatment of Epiglottitis

After you reach the emergency room, you should let the staff know that you are concerned about this illness. Children who may have epiglottitis should not treated in such away as to create distress and disturbance. The concern is that the epiglottis will “spasm” and shut the wind pipe (larynx) and the child will not be able to breath. Emergency room staff should have a radiograph of the child’s neck done to rule out epiglottitis before any other treatment is undertaken.

For the treatment of epiglottitis the child will be admitted to the hospital where a tube is passed through the nose or mouth and into the trachea allowing the child to breathe. Additionally, the child will be given intravenous antibiotics such as a cephalosporin to cure the bacterial infection.


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