What is croup?

Causes and Symptoms

Croup is an inflammation of the larynx, trachea, and upper bronchial tubes of the lungs affecting children between the ages of six months and five years. Two-year-olds seem to be the most commonly affected. The inflammation of the trachea causes a narrowing of the child’s already small airways, making breathing difficult. Technically, croup is a syndrome, or collection of symptoms associated with several different kinds of infections. These symptoms include hoarseness, a distinctive cough most often described as “barky” and noisy, and labored breathing known as stridor.

Croup occurs in three different forms. The first, viral croup, usually begins with a cold and is most commonly caused by parainfluenza viruses. Indeed, studies indicate that the parainfluenza viruses are responsible for about 70 to 75 percent of croup cases. Viral croup is often accompanied by a low-grade fever. A second type of croup is called spasmodic croup. This condition tends to occur with changes of the weather or the seasons, and the child does not usually run a fever. Allergies are often thought to be responsible for this kind of croup. A third, but rare, form is a bacterial infection caused by mycoplasma. This form can be very serious and is often identified by the extreme difficulty that the child experiences with breathing.

Studies indicate that attacks of croup most commonly occur in October through March and generally strike at night. In general, boys are somewhat more likely to be affected by croup than are girls.

A serious, but rare, condition known as epiglottitis
can sometimes be mistaken for croup. In this condition, the epiglottis, the flap that covers the windpipe during swallowing, becomes inflamed and swollen, potentially cutting off the child’s air supply. The symptoms of epiglottitis are similar to those of croup, but the child’s difficulty in breathing is much more severe, and the child will often run a high fever, drool, and be unable to make voiced sounds. Epiglottitis develops quickly; a child’s life can be in jeopardy in only a few hours. Consequently, this condition must be treated as an emergency, requiring hospital care.

Treatment and Therapy

A number of treatments are generally used to bring relief to the child suffering from viral or spasmodic croup. The use of a cool mist humidifier can ward off an attack in the child who exhibits a tendency toward developing croup. A mild attack can also be alleviated through use of the humidifier. If the attack of croup is well under way or if it is severe, however, a cool mist humidifier may not be adequate. Many doctors recommend that after an attack of croup, a cool mist humidifier should be run in the child’s room for the next three or four evenings. Another commonly used treatment is to take the child, properly dressed, outside at night. Usually the cold, damp air will soothe the child’s inflamed airways.

Still another technique reported to relieve the symptoms of croup is to fill the bathroom with steam by running a hot shower. Setting the child in the steam-filled room for fifteen to twenty minutes often eases the child’s breathing. The most successful use of this treatment requires that the child be held, not placed on the floor, because steam rises.

Neither cough syrups nor antibiotics are appropriate treatments for croup. Cough syrups prevent the expulsion of phlegm, while antibiotics have no effect on viral infections. Croup caused by mycoplasma, however, is treated with an antibiotic, generally erythromycin.

Pediatricians recommend that the child’s doctor be called in the event of a croup attack. Serious attacks are generally treated in a hospital emergency room. There, the child may be given cortisone by injection or by mouth. In addition, hospitals can administer breathing treatments.

Bacterial croup is also treated at a hospital with antibiotics and an oxygen tent as needed. Indeed, immediate emergency room treatment is called for if there is a whistling sound in the breathing that seems to grow louder, if the child does not have enough breath to speak, or if the child is struggling to breathe.

Perspective and Prospects

Accounts of croup can be found in medical literature dating back to the eighteenth century. Membranous croup, also known as diphtheria, was a great killer of children and adults alike in the past. Immunization made this kind of croup extremely rare, however, by the mid-twentieth century.

During the last quarter of the twentieth century, doctors continued to research the uses of corticosteroids in the treatment of croup, as well as the most effective way to deliver these drugs.

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