Caplan's syndrome is seen in patients with rheumatoid arthritis (RA) and chronic silica inhalation. We present a patient with RA who presented with multiple pulmonary nodules. Biopsy of the nodules revealed silica crystals under polarized light. He continued treatment for RA and his pulmonary nodules remained stable. However, he subsequently developed renal failure with nephrotic range proteinuria. We discuss silica and the associated autoimmunity in patients with chronic occupational exposure.
Background: Caplan's syndrome also known as rheumatoid pneumoconiosis is a disease entity that is seen in patients with rheumatoid arthritis (RA) exposed to chronic silica and inorganic dust [1,2]. Classically, they form peripheral well-defined pulmonary nodules with characteristic silica retained in the necrobiotic center. In addition, epidemiological data has shown some association with silica and autoimmunity [3]. We present a case of silica and asbestosis exposure in a patient with rheumatoid arthritis who developed rheumatoid pneumoconiosis and subsequent renal failure. We highlight this rare disease, progression as well as other associated complications.
Keywords: caplan’s syndrome; chronic silica inhalation; inorganic dust; peripheral; proteinuria; rheumatoid arthritis.