The first step is to determine the patient's risk of tuberculosis, including skin tuberculin reactivity (see previous section).
The clinical findings of chronic silicosis and tuberculosis tend to overlap, with low-grade fever, cough and malaise. The changes on imaging studies also may overlap. It is therefore important to actively look for both in populations at risk.
The changes of silicosis make the diagnosis of tuberculosis by chest X-ray difficult. Findings seen on imaging studies favoring the diagnosis of active tuberculosis include:
(1) thick-walled cavities
(2) pulmonary consolidation
(3) tree-in-bud pattern
(4) asymmetry in pulmonary nodules
(5) rapid disease progression
Laboratory testing should include sputum smears and cultures for acid fast bacilli.
Differential diagnosis - these conditions need to be excluded:
(1) deep fungal infection
(2) lung cancer
