ILD / DPLD

Sarcoidosis

Added by Dr. Andrew · Last updated 2024-01-15

Overview

Sarcoidosis is a multisystem granulomatous disease of unknown etiology, most commonly affecting the lungs and lymph nodes. It predominantly affects adults aged 20–40 and is more common and severe in Black Americans. Diagnosis requires compatible clinical/radiologic findings plus non-caseating granulomas on biopsy.

Key Points

1Pulmonary stages: Stage I (BHL only), II (BHL + parenchymal), III (parenchymal only), IV (fibrosis)
2Löfgren syndrome: BHL + erythema nodosum + arthritis — excellent prognosis, often self-resolving
3Heerfordt syndrome: uveitis + parotitis + facial nerve palsy + fever
4Serum ACE elevated in ~60% — not specific, useful for monitoring
5Treatment: corticosteroids for symptomatic/progressive disease; hydroxychloroquine for skin/hypercalcemia
6Cardiac sarcoidosis: complete heart block, VT, sudden death — requires ICD consideration

Clinical Pearls

BAL: lymphocytosis with CD4:CD8 ratio >3.5 supports sarcoidosis
Hypercalcemia: from 1,25-OH vitamin D production by macrophages
Neurosarcoidosis: cranial nerve palsies (especially CN VII), meningitis, hypothalamic dysfunction
Endobronchial sarcoidosis: cobblestoning of mucosa on bronchoscopy

Board High-Yield

Exam Focus

Stage I sarcoidosis: 60–80% spontaneous remission — observation is appropriate
Löfgren syndrome: excellent prognosis, NSAIDs first, steroids if needed
Cardiac sarcoidosis: most common cause of death in sarcoidosis in Japan
Steroid-sparing agents: methotrexate, azathioprine, hydroxychloroquine
Bilateral hilar lymphadenopathy + young patient + erythema nodosum = Löfgren syndrome

ABIM Exam Weight

10%

Diffuse Parenchymal Lung Disease represents approximately 10% of the PCCM certification exam.