Chapter 33-12: Sarcoidosis

TEXTBOOK PRESENTATION

When lung symptoms predominate, a patient in his 20s or 30s presents with dyspnea, cough, and/or wheezing. The clinical presentation may be indistinguishable from asthma. Because sarcoidosis is a multisystem disease, it may also present with symptoms caused by skin, eye, heart, or neurologic involvement. It is also occasionally diagnosed based on chest film findings in a patient without symptoms of sarcoidosis.

DISEASE HIGHLIGHTS

1. Sarcoidosis is a multisystem inflammatory disease.

2. The etiology of sarcoidosis is unknown. It is the result of a cell-mediated immune reaction that causes noncaseating granulomas. It is generally thought that, for a patient to develop sarcoidosis, he must have a genetic predisposition and then be exposed to certain triggering antigens.

3. The most commonly effected organs are the lungs, skin, eyes, heart, and CNS

   1. The lungs are affected in 90% of patients

      1. Common findings are asymptomatic hilar lymphadenopathy, restrictive lung disease with a decreased DLCO, and obstructive lung disease.

      2. Patients may present with dyspnea, cough, chest pain or wheezing.

   2. Symptoms of skin involvement are widely variable and occur in about 30% of patients.

   3. Any part of the eye can be affected by sarcoid and about 25% of patients with sarcoidosis have eye involvement.

   4. Cardiac sarcoidosis

      1. Often not clinically apparent but commonly found on autopsies.

      2. Cardiac sarcoid can cause syncope, heart failure, or sudden death.

      3. Sarcoidosis is a common cause of “idiopathic” 2nd or 3rd degree AV block in pts ≤ 60.

   5. Neurosarcoidosis

      1. Cranial nerve involvement is most common.

      2. Other common presentations of neurosarcoidosis are ataxia, cognitive dysfunction, headache, and seizures.

      3. Sarcoidosis also can affect the pituitary gland or spinal cord.

EVIDENCE-BASED DIAGNOSIS

1. The diagnosis of sarcoidosis is made when there is appropriate clinical suspicion and histologic evidence of noncaseating granulomas.

2. Biopsy

   1. Any accessible lesion can be biopsied. Lymph nodes and skin biopsies are most commonly used.

   2. Transbronchial biopsy has a diagnostic yield of 85%.

3. When patients present with Löfgren syndrome (erythema nodosum, hilar adenopathy, and polyarthralgias), the diagnosis of sarcoidosis is generally considered certain without biopsy.

4. The Siltzbach classification system is often used to describe sarcoidosis.

   1. Stage 0: normal appearance at chest radiography

   2. Stage 1: lymphadenopathy on chest radiography

   3. Stage 2: lymphadenopathy and parenchymal lung disease

   4. Stage 3: parenchymal lung disease only

   5. Stage 4: pulmonary fibrosis

5. ACE levels are insensitive and nonspecific and should not be used for diagnosing sarcoidosis.

TREATMENT

1. Most patients with sarcoidosis do not require treatment.

2. When patients with sarcoidosis do require treatment, it is generally because their disease is clinically active.

3. Corticosteroids remain the mainstay of treatment.

4. Methotrexate and infliximab are also considered effective and are used in patients who require long-term therapy.