Association of Silicosis and Dermatomyositis: Case Report and Literature Review

Abstract

The association between silicosis and autoimmune diseases is not uncommon. Silicosis is well correlated with rheumatoid arthritis and systemic lupus erythematosus. However, cases of dermatomyositis associated with silicosis are relatively understudied. We report a case of a 59-year-old man with a history of cardiac, respiratory, and systemic symptoms for the duration of a year, who present to the ER with acute dyspnea, fever, chest pain, and dry cough, and was diagnosed with silicosis and dermatomyositis. In this case report, we discuss the workup done in order to reach the diagnosis, as well as the pathological mechanism that might have led to the emergence of those two entities in the same patient.

Keywords: autoimmune disease; dermatomyositis; pulmonary involvement; silicosis; stonecutter.

Figure 1. Chest x-ray upon admission: PA view, arrows showing bilateral diffuse infiltrates. Cardiomegaly is also noticed, later confirmed on CT and echocardiography.

PA: posteroanterior

Figure 2. Parasternal long-axis echocardiogrpahy showing pericardial effusion, suggesting pericarditis.

LV: left ventricle; LA: left atrium; RV: right ventricle

Figure 3. Chest CT scan: lung parenchyma window showing architectural distortion with bronchiectasis, bilateral apical and basal honeycombing pattern with diffuse perilobular septal thickening, and the presence of diffuse perilobular bilateral basal infiltrates.

Figure 4. Proximal quadriceps muscle biopsy, showing features suggestive of myositis; inflammatory infiltrates of mononuclear cells in the endomysium, non-necrotic fibers surrounded and invaded by inflammatory cells.