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 condition where the trachea (the tube carrying air to the lungs) and the vocal cords are swollen and may have some muscle spasm. It's usually caused by a virus. Croup causes a hoarse, barky cough (like the barking of a seal) and noisy breathing. Fever, runny nose, and a hoarse voice may also be present. If your child's croup was caused by a virus, it may have easily been caught from someone who has a cold or respiratory infection.