Croup (or laryngotracheobronchitis) is caused by a virus and leads to swelling inside the throat. This swelling causes problems with normal breathing. People with croup can have a "barking"cough, stridor (a high-pitched wheezing sound), and hoarseness. Croup symptoms often get worse at night. Taking steroids by mouth can treat the condition. Sometimes epinephrine is used in more severe cases. Hospitalization is rarely required.