<unk> , also known as laryngotracheobronchitis, is a type of respiratory infection that is usually caused by a virus. The infection leads to swelling inside the trachea, which interferes with normal breathing and produces the classic symptoms of "barking/brassy" cough, inspiratory stridor and a hoarse voice. Fever and runny nose may also be present. These symptoms may be mild, moderate, or severe. Often it starts or is worse at night and normally lasts one to two days.<unk>  can be caused by a number of viruses including parainfluenza and influenza virus. Rarely is it due to a bacterial infection.<unk>  is typically diagnosed based on signs and symptoms after potentially more severe causes, such as epiglottitis or an airway foreign body, have been ruled out. Further investigations, such as blood tests, X-rays and cultures, are usually not needed. Many cases of<unk>  are preventable by immunization for influenza and diphtheria. Most cases of<unk>  are mild and the child can be treated at home with supportive care.<unk>  is usually treated with a single dose of steroids by mouth. In more severe cases inhaled epinephrine may also be used. Hospitalization is required in one to five percent of cases.<unk>  is a relatively common condition that affects about 15% of children at some point. It most commonly occurs between six months and five years of age but may rarely be seen in children as old as fifteen. It is slightly more common in males than females. It occurs most often in autumn. Before vaccination,<unk>  was frequently caused by diphtheria and was often fatal. This cause is now very rare in the Western world due to the success of the diphtheria vaccine.
Croup
Foreign body
Bronchorrhea
Epiglottitis
Tonsillitis
Tracheitis
Laryngitis
Post-nasal drip