what causes croup in infants
What is croup? Croup is a disease caused by a virus, bacteria, allergies, and inhaled irritants that leads to swelling in the airways and problems breathing. A child may have stridor, which is a high-pitched sound usually heard when the child breathes in (inspiration). What causes croup? Croup is most commonly caused by viruses. It is sometimes, but rarely, caused by bacteria, allergies, or reflux from the stomach. Croup is caused by a variety of different viruses. The most common virus is the parainfluenza virus. Other viruses may include: Respiratory syncytial virus (RSV) Influenza virus. Measles. Adenovirus. Enteroviruses