Overview
Definition
A multisystem inflammatory disease of unknown etiology characterized by the formation of non-caseating granulomas in various organs, most commonly the lungs and lymphatic system.
Epidemiology
Higher prevalence in African Americans and Northern Europeans. Typically presents in young adults (20-40 years).
Etiology & Risk Factors
- Unknown. Suspected exaggerated immune response to an unidentified environmental or infectious antigen in genetically susceptible individuals.
Clinical Symptoms
- Lungs (90%): Dry cough, dyspnea, chest pain
- Skin: Erythema nodosum, lupus pernio (pathognomonic)
- Eyes: Anterior uveitis (blurry vision, photophobia)
- Systemic: Fever, weight loss, night sweats, fatigue
Clinical Approach
Diagnosis
- Chest X-ray: Bilateral Hilar Lymphadenopathy (BHL) is classic
- Biopsy (transbronchial or of affected skin/lymph node): Non-caseating granulomas (must rule out TB/fungal infections first)
- Labs: Elevated ACE level, Hypercalcemia (granulomas produce 1-alpha-hydroxylase turning Vitamin D active)
Management
- Asymptomatic: Observation (many undergo spontaneous remission)
- Symptomatic/Organ threatening: Systemic Corticosteroids (first-line)
- Steroid-sparing agents: Methotrexate, Azathioprine, Infliximab (for refractory cases)
Complications
- Pulmonary fibrosis (Stage IV)
- Blindness (if uveitis is untreated)
- Cardiac sarcoidosis (fatal arrhythmias, heart failure)
- Neurosarcoidosis