The cough of a baby suffering from croup sounds like a small dog barking exhaustively. Affecting mostly the very youngest children and caused mostly by a various viral infections, this disorder also known as laryngotracheobronchitis is often identified by an x-ray examination that reveals what is known as the steeple sign in the throat. This narrow, pyramid shape indicates blockage in the trachea near the vocal chords but only when the x-ray is taken from the front to the back, the anteroposterior view.
Babies are most prone to getting this tracheal disorder, which reveals itself in not only the distinctive cough but also in a symptom known as inspiratory stridor, a labored wheezing. Since coughing and wheezing can be caused by other disorders, viral infections and even blockages of the throat, radiology is used to confirm a doctor's examination room diagnosis of viral croup. The steeple sign and other radiological discoveries can help secure an accurate diagnosis and the proper treatment.
According to the journal Radiology, the steeple sign is caused by graduated swelling of the the inner lining of the trachea. Called the mucosa, this lining becomes narrower as it rises to the glottis, or vocal chords. The result is a radiological image that reveals a stark inverted "V" instead of the normal subglottal region, which resembles instead an inverted "U."
When a doctor confirms croup through a steeple sign, the treatment could go in a few directions. According to the National Institutes of Health (NIH), a croup blockage typically goes away within a week, if caused by a viral infection. If a bacterial infection has caused the steeple sign, then antibiotics might be needed. Some doctors administer corticosteroid injections or medications with epinephrine to lessen the discomfort of croup and improve airflow, while others recommend an aerosol breathing treatment. At home, an anti-inflammatory, over-the-counter pain reliever might help with other problems like fever, as could the services of a humidifier or a steamer, though cold medicine is not advised to treat this type of cough.
A steeple sign could be an indication of a more serious condition that demands immediate medical attention. In minor form, physicians may recommend just observation and comfort-related treatment at home. An airway obstruction more serious than croup could be the problem, though. Some conditions in the very young, according to the NIH, could start with croup and lead to a collapsed lung, dehydration, epiglottitis and other life-threatening problems. These latter conditions, of course, have more symptoms than wheezing and a barking cough.