Laryngotracheitis or croup are a variety of respiratory diseases of children. Most diseases are between 6 months and 3 years, and is more common in men, and is rare in children over 6 years. They are more common when the cold begins in the autumn and early winter months. The most common cause is a viral infection that causes swelling of the larynx and trachea. Initially, the virus infects the nose and throat and then spreads to the larynx and trachea. Thus, the infection progresses into the windpipe and becomes swollen, with obstruction of the space through which air enters the lungs. Laryngotracheitis is often mild, and usually lasts less than a week, although symptoms may become severe and can be life threatening. Symptoms usually start with nasal irritation and congestion, progressing after 12 to 48h having trouble breathing, barking cough and hoarseness. Other symptoms may include fever, rash, conjunctivitis and even swelling of the lymph nodes. Treatment depends on the severity of symptoms and the risk of deterioration. Children who do not have symptoms of severe laryngotracheitis usually treated conservatively at home, but a child with moderate or severe risk of worsening symptoms must be urgently addressed.