Season One Edit. Beckett's initial relationship with Castle was strained because she viewed him as immature and reckless. She suspected (correctly) that Castle was using his research as an excuse to pursue her, and only tolerated his presence at the request of Captain Montgomery.
What causes croup in children. Croup in children is most often caused by the parainfluenza virus, a respiratory virus not related to the flu. But it can also be caused by other respiratory viruses including the flu. Yes, croup is contagious.
Croup is a common infection that causes swelling in the trachea (windpipe) and larynx (voice box). Croup occurs in children six months to 12 years of age. It is most common in children one to three years of age. Because croup is caused by a virus, it can spread to other children through coughing and sneezing. The virus also is spread by dirty hands, shared toys, and shared drinking glasses or spoons and forks.