义膜性喉炎（或称喉气管支气管炎）是由上呼吸道病毒感染引起的。感染导致咽喉内部肿胀，进而引起呼吸障碍。义膜性喉炎患者可能有压迫性咳嗽、喘鸣（高音调的哮鸣），并伴有声音嘶哑。义膜性喉炎症状通常会在夜间加重。单剂量口服类固醇可以治疗这种病症。更严重的情况有时会使用肾上腺素。很少需要住院治疗。

医生根据患者体征和症状确定是否为义膜性喉炎，并排除更严重的致病原因（例如，会厌炎或呼吸道异物）。通常不需要验血，做X-射线检测和培养。义膜性喉炎为常见疾病，约15％的儿童会患此病，通常集中在在6个月和5-6岁的年龄段。青少年和成年人很少患此病。

Croup is a type of respiratory infection that is usually caused by a virus. The infection leads to swelling inside the wind pipe, which interferes with normal breathing and produces the classic symptoms of "barking" cough, stridor, and a hoarse voice. Fever and runny nose may also be present. These symptoms may be mild, moderate, or severe. Often it starts or is worse at night. It normally lasts one to two days.