Croup causes swelling of the vocal cords (larynx) and windpipe (trachea). Due to the swelling, the airway below the vocal cords becomes narrow and can make breathing difficult and noisy. Many times, your child may develop a runny nose and congestion, which may then progress to a dry cough. The cough sounds like a barking seal. Croup is most commonly caused by a viral infection. It is most common in children between 6 months and 5 years. If your child develops croup, sitting in a steam bath for 10-15 minutes may help. A cool mist humidifier may also be used. If your child is not improving or develops difficulty breathing, severe coughing spells, or high fever, call our office or go to the nearest emergency room.