Croup is an inflammation of the voice box (larynx) and windpipe (trachea). When a child has croup, the airway just below the vocal cords becomes swollen and narrow. This makes breathing noisy and difficult.

Some children get croup often, such as whenever they have a respiratory illness. Children are most likely to get croup between 6 months and 3 years of age. After age 3, it is not as common because the windpipe is larger, so swelling is less likely to get in the way of breathing. Croup can occur at any time of the year, but it is more common between October and March.

There are two different types of croup:

• Spasmodic croup is usually caused by a mild upper respiratory infection or allergy. It is often frightening because it comes on suddenly in the middle of the night. Your child may go to bed with a mild cold and wake up in a few hours, gasping for breath. He will also be hoarse and have a cough that sounds like a seal barking. Most children with spasmodic croup do not have a fever. This type of croup can reoccur.
• Viral croup results from a viral infection in the voice box and windpipe. This kind of croup often starts with a cold that slowly develops into a barking cough. As your child's airway swells and she secretes more fluid, it becomes harder for her to breathe. Her breathing will also get noisier, and it may make a coarse musical sound each time she breathes in. This condition is called stridor. Most children with viral croup have a low fever, but some have temperatures up to 104°F.

As your child's effort to breathe increases, he may stop eating and drinking. He also may become too tired to cough, although you will hear the stridor more with each breath. The danger with croup accompanied by stridor is that the airway will keep swelling. If this happens, it may reach a point where your child cannot breathe at all.

Stridor is common with mild croup, especially when a child is crying or moving actively. But if a child has stridor while resting, it can be a sign of severe croup.

Treating Croup

If your child wakes up in the middle of the night with croup, take her into the bathroom. Close the door and turn the shower on the hottest setting to let the bathroom steam up. Sit in the steamy bathroom with your child. Within 15 to 20 minutes, the warm, moist air should help her breathing. (She will still have the barking cough, though.)

For the rest of that night and 2 to 3 nights after, try to use a cold-water vaporizer or humidifier in your child's room. Sometimes another attack of croup will occur the same night or the next. If it does, repeat the steam treatment in the bathroom. Steam almost always works. If it does not, take your child outdoors for a few minutes. Inhaling moist, cool night air may loosen up the air passages so that he can breathe more freely. If that does not help, consult your pediatrician about other options. If your child's breathing becomes a serious struggle, call for emergency medical services. (In most areas, dial 911.)

Never try to open your child's airway with your finger. Breathing is being blocked by swollen tissue out of your reach, so you cannot clear it away. Besides, putting your finger in your child's throat will only upset her. This can make her breathing even more difficult. For the same reasons, do not force your child to throw up. If she does happen to vomit, hold her head down and then quickly sit her back up once she is finished.

Your pediatrician will ask if your child's breathing is better after the steam treatment. If it is not, your pediatrician may prescribe a steroid medication to reduce swelling in the throat or shorten the illness. Although it has not been firmly proven that this works, treatment with a steroid for 5 days or less should do no harm.

Antibiotics, which treat bacteria, are not helpful for croup because the problem is almost always caused by a virus or allergy. Cough syrups are of little use too, because they do not affect the larynx or trachea, where the infection is located. These also may get in the way of your child coughing up the mucus from the infection.

If you suspect your child has croup, call your pediatrician—even if it is the middle of the night. Also, listen closely to your child's breathing. Call for emergency medical services immediately if he:

• makes a whistling sound that gets louder with each breath
• cannot speak for lack of breath
• seems to be struggling to get a breath
• seems very pale or has a bluish mouth or fingernails
• has stridor when resting
• drools or has extreme difficulty swallowing saliva