Croup

CroupCroup is a common upper respiratory tract infection that can affect young children.Croup typically occurs in the fall and winter months and is caused by parainfluenza or influenza viruses, adenovirus, or respiratory syncytial virus.These viruses cause inflammation of the larynx (voice box) and the trachea; hence, the clinical name of croup is laryngotracheitis.The inflammation leads to swelling and redness of these structures, which can affect a child's voice as well as ability to breathe.