Sarcoidosis Flashcards
What is sarcoidosis?
Sarcoidosis is a chronic granulomatous disease characterized by non-caseating granulomas in multiple organs. Patients classically have hilar lymphadenopathy, nodular pulmonary infiltrates, and a history of anterior uveitis. Sarcoidosis is an inflammatory disorder of unknown etiology that occurs most commonly in younger, African American patients. It is characterized on histology by the presence of noncaseating granulomas (collections of tightly clustered, epithelioid macrophages with abundant pink cytoplasm surrounded by a rim of mononuclear cells without central necrosis). Multinucleated giant cells, formed by macrophage fusion, are frequently seen. Sarcoidosis primarily involves the lungs, causing nodular or interstitial infiltrates. However, extrapulmonary manifestations are common and can involve the lymph nodes eg, hilar adenopathy), eyes (eg, anterior uveitis, skin (eg, erythematous nodular rashes), CNS (eg, neurosarcoidosis, and internal organs (eg, heart, liver). Salivary glands (eg, parotid, as in this patient) are involved in up to 5% of patients. Constitutional symptoms, including fatigue, weight loss, and night sweats, can also occur.
Which demographic is most commonly affected by sarcoidosis?
Young Black females.
What is the most commonly affected organ in sarcoidosis?
The lungs.
What are the primary pulmonary symptoms of sarcoidosis?
Cough, dyspnea, chest pain, bilateral hilar lymphadenopathy, and interstitial infiltrates.
What type of lung disease is sarcoidosis classified as?
Restrictive lung disease.
What is lupus pernio, and what disease is it associated with?
A chronic, violaceous skin lesion on the face associated with sarcoidosis.
What are other skin findings in sarcoidosis?
Plaques, nodules, papules, atrophic or ulcerative lesions.
What MSK symptoms are associated with sarcoidosis?
Acute or chronic polyarthritis, myopathies, and erythema nodosum.
What is the most common ophthalmologic manifestation of sarcoidosis?
Anterior or posterior uveitis.
What central nervous system manifestations can occur in sarcoidosis?
Neurosarcoid, hypopituitarism, aseptic meningitis, central diabetes insipidus, cranial mononeuropathy, facial nerve palsy.
How do you diagnose central diabetes insipidus in sarcoidosis?
- Water deprivation test: urine osmolality remains low, plasma osmolality remains high.
- Responds to desmopressin due to sarcoidosis causing central DI.
How do you differentiate central vs nephrogenic diabetes insipidus?
Central DI responds to desmopressin, while nephrogenic DI does not.
What cardiac conditions are associated with sarcoidosis?
Restrictive or dilated cardiomyopathy, pericarditis, conduction disease (AV blocks, bundle branch blocks).
What ECG findings may suggest cardiac sarcoidosis?
AV blocks or bundle branch blocks.
What is the key finding in pericarditis that can be seen in sarcoidosis?
Diffuse ST-segment elevations and PR depression.
What systemic findings may be seen in sarcoidosis?
- Peripheral lymphadenopathy
- Splenomegaly
- Hypercalcemia
- Hypervitaminosis D
- Elevated ACE levels
Why does sarcoidosis cause hypercalcemia?
Increased 1-alpha-hydroxylase activity within the macrophages leads to increased active vitamin D production.
How do PTH and calcium levels present in sarcoidosis?
Low PTH, high vitamin D, high calcium, hypercalciuria.
What is seen in the bronchoalveolar lavage of a sarcoidosis patient?
Elevated CD4/CD8 ratio.
What are the four key features of Lofgren syndrome?
Bilateral hilar lymphadenopathy, fever, polyarthritis, and erythema nodosum.
What is the first-line imaging modality for suspected pulmonary sarcoidosis?
Chest X-ray (bilateral hilar lymphadenopathy).
What does a CT scan of the lungs show in sarcoidosis?
Pulmonary infiltrates and fibrosis.
What is the gold standard for diagnosing sarcoidosis?
Biopsy showing non-caseating granulomas.
What is the preferred site for biopsy in sarcoidosis?
Most accessible lesion (cutaneous, superficial lymph node, or endobronchial biopsy).
How is asymptomatic sarcoidosis managed?
Observation, as it may resolve spontaneously.
What percentage of sarcoidosis cases undergo spontaneous remission?
20-70%.
How is symptomatic sarcoidosis treated?
Corticosteroids (first-line treatment).
What is the treatment for dermatologic sarcoidosis?
Topical, intralesional, or systemic corticosteroids.
What is the treatment for sarcoid-associated arthritis?
NSAIDs or corticosteroids.
What factors predict a worse prognosis in sarcoidosis?
Advanced pulmonary disease, extrapulmonary organ involvement, and African American ethnicity.
