Acute bronchitis

Definition:

An inflammation of the main air passages to the lungs (the bronchi).

Causes, incidence, and risk factors:

Bronchitis generally follows a viral respiratory infection and typically appears just as the symptoms of the initial infection are waning. The viral infection, which may be caused by any number of respiratory viruses including the rhinoviruses which cause the common cold, produces bronchial inflammation which sets the stage for bronchitis and secondary bacterial infection.

Early symptoms may include a tickle deep in the throat just above the sternal notch which progresses into an irritating dry cough. As the infection progresses the cough may become productive with thick yellow sputum (purulent sputum) which is occasionally blood streaked. Associated symptoms may include fever, malaise, chest pain and shortness of breath.

Infants generally develop other respiratory complications such as bronchiolitis or pneumonia while older children and adolescents develop typical adult symptoms of bronchitis.

Risk factors include recent illnesses that have lowered resistance to infection, a preceding viral respiratory infection or chronic pulmonary problems. The incidence is 4 out of 100 people.