Beryllium is a lightweight metal used in the aerospace and electronic industries and in the manufacture of thermal couplings, atomic reactors, and fluorescent lights. Exposure to beryllium can result in acute or chronic disease. Acute berylliosis results from short-term exposure to high levels of soluble salts of beryllium, leading to a chemical pneumonitis with development of diffuse alveolar damage.

Chronic berylliosis manifests after several years of low-level exposure, resulting in granulomatous inflammation, and pulmonary fibrosis later in the course of disease. Occupational history of beryllium exposure is essential for diagnosis. Diagnosis can be confirmed by demonstration of beryllium in the tissues using electron energy loss spectrometry (EELS), secondary ion mass spectrometry (SIMS), or laser microprobe mass analyzer (LAMMA). Differential diagnosis includes sarcoidosis and hypersensitivity pneumonitis.