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nation reveals bilateral crackles. Some individuals have subcutaneous raised nodules on exposed skin surfaces (eg, hands, arms, neck, face) caused by pene- tration of beryllium dust through the skin. In ad-
vanced cases, cyanosis, digital clubbing, and signs of right heart failure secondary to cor pulmonale may ap- pear. Pulmonary function test results may be normal in early disease. As disease progresses, obstructive, restrictive, mixed patterns, and impaired diffusion capacity may occur , with obstructive changes occurring early. Cardiopulmonary exercise testing abnormalities of ventilation and gas exchange are the most sensitive physiologic changes .
Radiographic changes are similar to sarcoidosis and include diffuse bilateral small opacities, predomi- nantly in the middle and upper lung fields. Bilateral adenopathy is also seen, but less frequently than in sarcoidosis. Scadding stage I radiographs (hilar ade- nopathy without infiltrates) are unusual . HRCT is more sensitive than plain film but also may be nega- tive in up to 25% of biopsy-proven screening iden- tified cases [81,82]. HRCT findings include bilateral small nodules (usually distributed along broncho- vascular bundles), septal lines, bronchial wall thick- ening, and ground-glass attenuation . Enlarged hilar nodes are detected by HRCT in approximately one third of cases. In advanced disease, honey- combing may occur. Conglomerate masses and em- physema also are seen in advanced cases.
Published diagnostic algorithms center on the BeLPT [75,83]. Diagnosis requires a history of exposure, demonstration of a beryllium-specific, cell-mediated immune response in blood or broncho- alveolar lavage, and evidence of lung inflammation (granulomas, mononuclear cell interstitial infiltrates, or lymphocytic alveolitis) at bronchoscopy. When bronchoscopy with biopsy cannot be performed safely, one can make the diagnosis based on a positive blood BeLPT plus evidence of diffuse lung disease (ie, typical radiographic or CT abnormalities, abnor- mal physiology, lavage lymphocytosis, or granuloma- tous inflammation).
clinical experience and multiple published case series [18,74]. Supportive care also is important.
Emerging occupational interstitial lung diseases
Occupational ILD secondary to previously un- described agents continues to occur, and clinicians must stay alert to this possibility. Two recently re- ported examples that illustrate the potential to de- scribe new forms of work-related ILD include nylon flock worker’s lung and textile sprayer’s lung. Ny- lon flock worker’s lung was first described in 1998 . It is an ILD that occurs in workers exposed to random cut nylon flock (a material that imparts a velvety surface when applied to adhesive fabrics or objects) . This disease occurs after a variable latency period (ranging from 1–30 years), and symp- toms include persistent dry cough and dyspnea. Physical examination reveals crackles. The chest radiograph reveals reticulonodular infiltrates, and the main HRCT findings include patchy ground-glass attenuation and micronodules . Reticular abnor- malities, consolidation, and traction bronchiectasis also occur in a few patients. Lung biopsies reveal a lymphocytic bronchiolitis and peribronchiolitis with associated lymphoid aggregates . The only known effective treatment is removal from exposure.
Textile sprayer’s lung, or Ardystil syndrome, was first reported in 1994 . Initial and subsequent reports described an epidemic of organizing pneu- monia in textile printing sprayers using the chemical Acramin-FWN [89–91]. The most common symp- toms are cough, epistaxis, and dyspnea. Radiogra- phy and HRCT reveal bilateral patchy consolidation. Small nodular infiltrates were seen on some HRCTs. Pulmonary function tests revealed restriction or a reduced DLCO. Biopsies revealed organizing pneu- monia. Many patients developed progressive disease despite removal from exposure and corticosteroids.
The natural history of CBD is variable. Most patients demonstrate a slow progression of symptoms and functional abnormalities. Some patients, however, have a more rapid progression, whereas others remain stable for extended periods. Reduction or removal from exposure is recommended for all patients with beryllium sensitivity or CBD. Pharmacologic treat- ment is generally initiated in the setting of symptoms with severe or progressive functional abnormalities. Corticosteroids remain the mainstay of treatment. No randomized trials have documented corticosteroid effectiveness, but its use is supported by extensive
Occupational ILD is a diverse group of prevent- able pulmonary diseases that accounts for a significant portion of all ILD. There are numerous well-described and poorly characterized causative agents, and new causative exposures continue to be described. Diag- nosis requires a high degree of clinical suspicion and a thorough occupational and environmental history. Treatment is similar to idiopathic forms of ILD but also includes removal from exposure. Primary and secondary disease prevention should be pursued for