Bronchial infections with viral and bacterial microorganisms are responsible for a significant percentage of ambulatory care visits and are among the principle causes of time lost from work. These infections occur in individuals with and without underlying chronic bronchial disease, each with important differences in etiology, clinical presentation, laboratory findings, and requirements for therapy.

ACUTE BRONCHITIS

Acute infectious bronchitis in individuals without underlying chronic lung disease is most commonly caused by viral pathogens, with a lesser contribution by Mycoplasma, Chlamydophila, and Legionella. The relative frequencies of these etiologies vary with time and place and have epidemic-like characteristics in the population. The clinical presentation is usually abrupt and is characterized by the onset of cough, which may be productive of scanty sputum. There are variable associated symptoms, including coryza, sore throat, burning sensation in tracheal area, malaise, feverishness, chilliness, and other symptoms of viremia. Wheezing and dyspnea are unusual symptoms in adults but may be present in young children, in which case it can be confused with asthma. All of these symptoms are most troublesome in the first few days of the infection and should significantly improve or resolve within 1 week. Medical intervention is rarely sought or required, and symptomatic therapy usually suffices. Routine laboratory studies are rarely indicated and are not likely to be useful. If the patient produces sputum, the cytologic findings are of neutrophils with swollen bronchial epithelial cells, which may demonstrate vacuolization.