Bronchitis laboratory tests

Overview
Acute bronchitis is usually a diagnosis of exclusion. A careful history and physical examination are very useful in doing a correct diagnosis. Other laboratory testings like antigen testing via multiplex pcr (polymerase chain reaction) and serological markers, can act as useful adjunct to the diagnosis. Nevertheless, these tests should be limited only for conditions when a pathogen is highly suspected, epidemic with a pathogen is present (influenza. These tests have limited availability and have not shown to be cost effective in outpatients department.

Antigen testing and Serological markers
Rapid antigen and serological tests have limited availability and are costly. However, it can be used to as an adjunct to diagnosis in certain conditions like: Other tests
 * The suspected organism is treatable
 * A epidemic with the pathogen is suspected (influenza).
 * Patient has typical presentation suggestive of pathogen. the infection is known to be circulating in the community, and the patient has suggestive symptoms or signs (e.g., testing for influenza during influenza season in patients with cough and fever)
 * A sputum sample showing neutrophil granulocytes (inflammatory white blood cells) and culture
 * A blood test would indicate inflammation (as indicated by a raised white blood cell count and elevated C-reactive protein).
 * Damage caused by irritation of the airways leads to inflammation and leads to neutrophils being present
 * A chest X-ray that reveals hyperinflation; collapse and consolidation of lung areas would support a diagnosis of pneumonia. Some conditions that predispose to bronchitis may be indicated by chest radiography.

Procalcitonin test
Procalcitonin are increased in bacterial infections and stay low in viral infections. Clinical trials testing its benefits as a tool to prescribe antibiotics for acute bronchitis if the cause is bacterial (procalcitonin levels are raised) have not found a significant difference.