A condition of breathing difficulty caused by infection, inflammation, and swelling of the upper airway (larynx, trachea, and bronchus). Croup is characterized by a "barking" cough.
Alternative Names
Viral croup; Acute laryngotracheobronchitis
Causes, incidence, and risk factors
Croup is usually caused by a viral infection with para-influenza virus, respiratory syncytial virus (RSV) , and influenza viruses A and B. These viruses are commonly present in the air, especially during the fall and winter. A bacterial infection leading to croup is most often caused by Hemophilus influenza (epiglotitis, a life-threatening infection). Croup most often occurs in children between 6 months and 3 years of age. The recognizable barking cough and noisy breathing ( stridor ) is caused by swelling in the upper airway (larynx, trachea, and bronchi). The child's breathing becomes more difficult and requires increasing physical effort. The child may be physically tired, but is unable to rest because of the increased breathing effort. The child may be restless , have a fever , and be working hard to keep breathing. Extra effort to breathe may be noticed as wider opening of the nasal openings during inhalation ( nasal flaring ); increased use of the muscles in the neck and chest; and unwillingness to lie down, rest, eat, or drink. In severe cases the child's lips and fingers may turn blue ( cyanosis ), indicating inadequate oxygen supply. In severe cases of croup there may be a bacterial superinfection of the upper airway. This condition is called bacterial tracheitis and requires intravenous antibiotics. If the epiglottis becomes infected, the entire windpipe can swell shut, a potentially fatal condition called epiglottitis .
Signs and tests
An examination shows chest retractions with breathing. Listening to the chest through a stethoscope ( auscultation of the breath sounds ) reveals prolonged inspiration or expiration, wheezing , and decreased breath sounds. An examination of throat may reveal red epiglottis. A neck X-ray may reveal a foreign object or narrowing of the trachea.
Treatment
Mild illness may be treated at home with supportive measures. Parents should stay calm -- this will help the child to stay calm. Warm or cool humidified air should be provided. A hot shower can provide warm steam, and the child can be held in the bathroom for 20 minutes. (Do not place the child in the shower.) Taking the child outside in the cold air is often helpful. Serious illness requires hospitalization. Increasing or persistent breathing difficulty , fatigue , bluish coloration of the skin , or dehydration indicates the need for medical attention or hospitalization. Aerosolized racemic epinephrine as well as oral dexamethasone (a steroid) help to shrink the upper airway swelling. Oxygen and humidity may be provided in an oxygen tent placed over a crib. A bacterial infection requires antibiotic therapy. Increasing obstruction of the airway requires intubation (placing a tube through the nose or mouth through the larynx into the main air passage to the lungs). Intravenous fluids are given for dehydration. In some cases, corticosteroids are prescribed.
Expectations (prognosis)
Viral croup usually goes away in 3 to 7 days. The outcome for bacterial croup is good with prompt treatment. If an airway obstruction is not treated promptly, respiratory distress (severe difficulty breathing ) and respiratory arrest can occur.
Calling your health care provider
In most cases, you should apply home treatment first.
Call your health care provider if severe symptoms persist for more than 1 hour. Call IMMEDIATELY or go to the emergency room if severe breathing difficulty , bluish coloration of the skin , fatigue , dehydration , or unconsciousness occurs. If your child is extremely irritable, with excessive drooling, be concerned that this is epiglottitis and call 911 for emergency transport to the closest hospital.
Prevention
Appropriate hygiene and avoiding closeness to or contact with others with respiratory infections can prevent some infections.