What is the workup and treatment for sarcoidosis?

Workup for Sarcoidosis

The diagnostic workup for sarcoidosis should include chest imaging, pulmonary function tests, and targeted evaluation of potentially affected organs, with cardiac MRI being the imaging study of choice for suspected cardiac involvement. 1, 2

Initial Diagnostic Evaluation

Essential Components

• Chest Imaging:

  • Chest radiography (initial screening)
  • High-resolution chest CT (HRCT) for detailed evaluation of lung parenchyma and lymph nodes 1

• Pulmonary Function Tests:

  • Forced vital capacity (FVC)
  • Forced expiratory volume in 1 second (FEV1)
  • Diffusing capacity of the lung for carbon monoxide (DLCO) 1

• Laboratory Studies:

  • Complete blood count
  • Comprehensive metabolic panel (liver and kidney function)
  • Serum calcium
  • Angiotensin-converting enzyme (ACE) levels
  • Inflammatory markers (ESR, CRP)

• Tissue Biopsy:

  • Non-caseating granulomas on histopathology from the most accessible involved organ
  • Transbronchial biopsy for pulmonary involvement
  • Endomyocardial biopsy has low sensitivity (25-50%) for cardiac sarcoidosis due to patchy nature of lesions 1, 2

Organ-Specific Evaluation

Cardiac Assessment

• Electrocardiogram (ECG) - to detect conduction abnormalities
• Holter monitoring - >100 ventricular ectopic beats in 24 hours is suggestive 1
• Echocardiography - to assess ventricular function, wall motion abnormalities, septal thickness 1
• Cardiac MRI with late gadolinium enhancement - imaging study of choice for cardiac sarcoidosis 1, 2
• PET with fluorodeoxyglucose - identifies inflammation with better diagnostic accuracy than older techniques 1, 2

Pulmonary Assessment

• 6-minute walk test - to assess exercise capacity and oxygen desaturation 1
• Transthoracic echocardiography - for patients with chronic exercise intolerance or suspected pulmonary hypertension 1

Other Organ Systems

• Ophthalmologic examination - for ocular involvement
• Skin examination - for cutaneous manifestations (pink-red to red-brown papules and plaques) 3
• Neurologic evaluation - if neurological symptoms are present

Treatment Approach

Pulmonary Sarcoidosis

1. First-line treatment: Glucocorticoids (prednisone)

   • Initial dose: 20-40 mg daily for 2 weeks to 2 months 4
   • Taper over 6-18 months if symptoms, PFTs, and radiographs improve 4
   • No additional benefit for treating pulmonary disease with more than 20 mg prednisone daily 1

2. Second-line agents (steroid-sparing):

   • Methotrexate (10-15 mg once weekly) 1, 5
   • Azathioprine (50-250 mg daily) 1, 4
   • Leflunomide (10-20 mg daily) 1
   • Mycophenolate mofetil (500-1500 mg twice daily) 1

3. Third-line agents:

   • Anti-TNF agents (infliximab, adalimumab) for refractory disease 1, 4

Cardiac Sarcoidosis

• Glucocorticoids at high dose (prednisone 40-60 mg daily), tapered slowly over months 1, 2
• ICD implantation for high-risk patients (survivors of cardiac arrest, sustained ventricular tachycardia, LVEF <35%) 2
• Standard heart failure management for reduced ejection fraction 2

Monitoring and Follow-up

• Regular assessment of pulmonary function (FVC, FEV1, DLCO)
• Chest imaging to evaluate response
• Monitoring for treatment-related complications
• More frequent monitoring (every 3-6 months) for high-risk patients 2

Prognosis

• Mortality rate for sarcoidosis over 5 years is approximately 7% 4
• Spontaneous remission rates by Scadding stage: 75% for Stage I, 65% for Stage II, 30% for Stage III 2, 4
• Stage IV has no chance of resolution 4
• Approximately 10-40% of patients develop progressive pulmonary disease 4

• 60% of deaths from sarcoidosis are due to advanced cardiopulmonary disease 4

Common Pitfalls to Avoid

1. Underdiagnosing cardiac involvement: Cardiac sarcoidosis may be clinically silent but carries significant mortality risk
2. Overreliance on endomyocardial biopsy: Low sensitivity due to patchy nature of lesions 1, 2
3. Inadequate treatment duration: At least 50% of patients started on glucocorticoids remain on treatment after 2 years 1, 2
4. Failure to monitor for treatment complications: Regular assessment for glucocorticoid side effects is essential
5. Underestimating risk of sudden death: Even in patients with preserved LVEF 2

By following this systematic approach to the workup and treatment of sarcoidosis, clinicians can optimize outcomes by ensuring timely diagnosis, appropriate treatment, and careful monitoring for disease progression and treatment complications.