What Is It?
Croup is a common respiratory illness in children that causes a change in breathing with a hoarse voice and a brassy, barking cough. Doctors sometimes call croup laryngotracheitis because it usually involves inflammation of the larynx (voice box) and trachea (windpipe).
Croup often is divided into two broad categories:
Infectious croup is caused by an infection with a virus, bacterium or other germ. In the United States, most cases of croup are caused by a virus. These infections usually occur in the fall and winter when people spend more time indoors.
Under these conditions, the virus spreads easily through coughing and sneezing. It also can travel on dirty hands and on things that have had contact with fluids from a sick person's nose or mouth. These include used tissues, toys, drinking glasses and eating utensils.