Caplan's Syndrome

Definition

Definition of Caplan's Syndrome
Caplan's syndrome (or Caplan's disease) is a combination of rheumatoid arthritis (RA) and pneumoconiosis that manifests as intrapulmonary nodules, which appear homogenous and well-defined on chest X-ray. The syndrome 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.

Symptoms

Symptoms of Caplan's Syndrome
Caplan's syndrome presents with cough and shortness of breath in conjunction with features of rheumatoid arthritis such painful joints and morning stiffness. Examination should reveal tender, swollen MCP joints and rheumatoid nodules; auscultation of the chest may reveal diffuse râles that do not disappear on coughing or taking a deep breath.

Causes

Causes of Caplan's Syndrome
Caplan's syndrome occurs only in patients with both RA and pneumoconiosis related to mining dust (coal, asbestos, silica).The condition occurs in miners (especially those working in anthracite coal-mines), asbestosis, silicosis and other pneumoconioses. There is probably also a genetic predisposition, and smoking is thought to be an aggravating factor.

Diagnosis

Diagnosis of Caplan's Syndrome

1. Chest radiology shows multiple, round, well defined nodules, usually 0.5-2.0 cm in diameter, which may cavitate and resemble tuberculosis.
2. Lung function tests may reveal a mixed restrictive and obstructive ventilatory defect with a loss of lung volume. There may also be irreversible airflow limitation and a reduced DLCO.
3. Rheumatoid factor, antinuclear antibodies, and non-organ specific antibodies may be present in the serum.
4. Silicosis and asbestosis must be considered in the differential with TB.

Treatment

Treatment of Caplan's Syndrome
Once tuberculosis has been excluded, treatment is with steroids. All exposure to coal dust must be stopped, and smoking cessation should be attempted. Rheumatoid arthritis should be treated normally with early use of DMARDs.

Prognosis

Prognosis of Caplan's Syndrome
The nodules may pre-date the appearance of rheumatoid arthritis by several years. Otherwise prognosis is as for RA; lung disease may remit spontaneously, but pulmonary fibrosis may also progress.

Prevention

Prevention of Caplan's Syndrome
People with rheumatoid arthritis should avoid exposure to hazardous dust.