Croup, or acute laryngotracheobronchitis, is an acute infectious respiratory disease of infants and children caused by infection of the larynx or the trachea - alone or together. It can cause partial or severe obstruction of the airway, which results in breathing difficulties and coughing. In some children it can be life-threatening.
Croup - Image Copyright: joshya / Shutterstock
Croup is most often caused by the parainfluenza virus, but may also be the result of infection with respiratory syncytial virus (RSV), adenoviruses, or the measles virus. Bacterial croup is also known to occur, as is croup due to allergic reactions, acid reflux or irritation of the airway by a foreign body. Croup usually affects children simply because their airways are narrower than in adults, making any swelling more dangerous and likely to block the air flow.
The affected child is most often between 3 months and 5 years of age, with the incidence peaking at around 24 months. Croup starts usually as an ordinary cold, but worsens after a few days. It is characterized by noisy breathing and a hoarse voice, although the most impressive feature is the barking cough, often likened to a seal barking. In addition, there may be difficulty with breathing, especially at night. The symptoms start mildly in most cases. They may last for up to a week, and are especially severe on the first and second nights.
Diagnosis and management
Croup is diagnosed on the basis of the symptoms and the cough. Physical examination will show various signs related to laryngeal inflammation and respiratory difficulty.
Croup in most cases responds to home care, under the advice of a medical professional. The child should be comforted because anxiety and fear exaggerate the obstruction and increase the breathing rate.
In many cases, moist air in the form of steam is used to relieve the obstruction. Cool air vaporizers may be helpful. This time-hallowed form of treatment has, however, no scientific backing.
Fever is treated with acetaminophen titrated according to the child’s body weight and age. In certain instances, antibiotics or steroid inhalers may be required, on the prescription of a doctor. Steroids help to relieve the airway obstruction, but require some time to act when taken systemically. Inhaled steroids act much faster.
Medical treatment is essential when the child is seriously distressed, tired out from the effort of breathing, or cyanosed because adequate oxygen is not reaching the body. Admission is required for approximately 5% of croupy children.
Hospital treatment may include nebulization with epinephrine to urgently bring down the inflammation in severe cases. Other measures include:
- The use of an oxygen tent to improve the oxygenation and thus reduce the work of breathing, consequently relieving the child
- Glucocorticoids to further reduce and keep down inflammatory swelling have been found to be highly effective in decreasing the need for hospital admission of such children; they may be given by inhalation, orally or intravenously
- Fluids for dehydration, either orally or more often intravenously
- Antibiotic therapy if there is actual or likely secondary infection
Reviewed by: Dr Tomislav Meštrović, MD, PhD