Contents
Combination of rheumatoid arthritis (RA) and pneumoconiosis due to immune hyperactivity through exposure to silica.
History:
Caplan syndrome, also known as rheumatoid pneumoconiosis is named after Dr. Anthony Caplan, a physician on the Cardiff Pneumoconiosis Panel, who identified the constellation of findings as a distinct entity in a 1953 publication. He followed this with further articles exploring the disease. Caplan syndrome was originally described in coal miners with progressive massive fibrosis.
Aetiology
- Work exposure to coal, asbestos, and/or silica causing pneumoconiosis in a patient with rheumatoid arthritis (RA)
- Smoking (aggravating factor)
Clinical features
Pulmonary symptoms:
- Cough, shortness of breath
Rheumatoid arthritis (RA) symptoms:
- Prolonged morning stiffness
- Symmetric arthritis in a systemic fashion

Physical examination:
- RA findings: Swollen joints, tender metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints
- Pulmonary findings: Rales, wheezes, and crackles
Diagnosis
Chest radiography:
- Multiple well-defined rounded nodules (0.5-5cm), distributed throughout the lungs but predominantly at the lung periphery

Management
Does not require treatment, and management should be focused on treating the extrapulmonary manifestations of rheumatoid arthritis in addition to the treatment of RA.
- Stop exposure to coal dust and smoking