Silicosis

Extensive or prolonged inhalation of free silica

Small, rounded opacities (silicotic nodules) throughout the lung

Calcification of peripheral hilar lymph nodes ("eggshell" calcification) strongly suggests silicosis

Incidence of pulmonary tuberculosis is increased in patients with silicosis

Simple silicosis is usually asymptomatic without effect on pulmonary function tests

Complicated silicosis presents with large conglomerate densities in the upper lung; dyspnea with restrictive and obstructive changes on pulmonary function tests is common

All patients require a tuberculin skin test and current chest radiograph

Patients with suspected old pulmonary tuberculosis should be treated with multidrug regimens