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Key Features

Essentials of Diagnosis

  • Symptoms related to

    • Lung

    • Skin

    • Eyes

    • Peripheral nerves

    • Liver

    • Kidney

    • Heart

    • Other tissues

  • Demonstration of noncaseating granulomas in biopsy specimen

  • Exclusion of other granulomatous disorders

General Considerations

  • A systemic disease of unknown etiology

  • Granulomatous inflammation of the lungs is present in 90% of cases

Demographics

  • Highest incidence in North American blacks and northern European whites

  • Among blacks, women are more frequently affected than men

  • Disease onset is usually in the third or fourth decade

Clinical Findings

Symptoms and Signs

  • Malaise, fever, and insidious dyspnea

  • Symptoms from erythema nodosum, iritis, peripheral neuropathy, arthritis or cardiomyopathy may also prompt initial evaluation

  • Some patients are asymptomatic, and diagnosis is made after abnormal findings are noted on chest radiograph

  • Crackles are uncommon on chest examination

  • Parotid gland enlargement, hepatosplenomegaly, and lymphadenopathy may be noted

  • Myocardial sarcoidosis is found in 5% of patients and can lead to

    • Restrictive cardiomyopathy

    • Cardiac dysrhythmias

    • Conduction disturbances

Differential Diagnosis

  • Other granulomatous diseases must be excluded

    • Tuberculosis

    • Histoplasmosis

    • Coccidioidomycosis

  • Lymphoma (including lymphocytic interstitial pneumonitis)

  • Idiopathic pulmonary fibrosis

  • Pneumoconiosis (especially berylliosis)

  • Syphilis

Diagnosis

Laboratory Tests

  • Leukopenia

  • Elevation of erythrocyte sedimentation rate

  • Hypercalcemia in 5%, hypercalciuria in 20%

  • Angiotensin-converting enzyme (ACE) levels

    • Commonly elevated in active disease

    • Neither sensitive nor specific enough to be of diagnostic value

  • Physiologic testing may reveal evidence of airflow obstruction, but restrictive changes with decreased lung volumes and diffusing capacity are more common

  • Skin test anergy is present in 70%

Imaging Studies

  • Radiographic findings are variable

    • Stage I: hilar adenopathy alone

    • Stage II: hilar adenopathy with parenchymal involvement

    • Stage III: parenchymal involvement alone

    • Stage IV: advanced fibrotic changes principally in the upper lobes

  • Parenchymal involvement usually manifests as diffuse reticular infiltrates, but focal infiltrates, acinar shadows, nodules, and rare cavitation are seen

  • Pleural effusion occurs in < 10% of patients

Diagnostic Procedures

  • ECG may show conduction disturbances and dysrhythmias

  • Biopsy demonstrating noncaseating granulomas is required for diagnosis

    • Easily accessible biopsy sites include lymph nodes, skin lesions, and salivary glands

    • Transbronchial biopsy has a yield of 75–90%

    • Some experts believe biopsy is unnecessary in stage I disease with a presentation highly suggestive of sarcoidosis

  • Bronchoalveolar lavage is usually characterized by an increase in lymphocytes with a high CD4/CD8 ratio; this may be used to follow disease activity, but not for diagnosis

Treatment

Medications

  • Corticosteroids (eg, oral prednisone, 0.5–1.0 mg/kg/day) are indicated for

    • Constitutional symptoms

    • Hypercalcemia

    • Iritis

    • Uveitis

    • Arthritis

    • CNS involvement

    • Cardiac involvement

    • Granulomatous hepatitis

    • Cutaneous lesions other than erythema nodosum

    • Progressive pulmonary lesions

  • Long-term therapy is usually required over months to years

  • Immunosuppressive medications, ...

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