Sarcoidosis

Sarcoidosis is a chronic inflammatory disease where the body forms small clusters of immune cells called granulomas in various organs. These granulomas can interfere with organ function and cause a wide range of symptoms, depending on where they form. The lungs and lymph nodes are most commonly affected, but sarcoidosis can involve the skin, eyes, heart, liver, brain, and other organs. It is considered an immune-mediated disease and is sometimes classified as autoimmune, although the exact mechanism is not fully understood.

General symptoms: Fatigue, Fever, Weight loss, Night sweats. Lung symptoms (most common): Persistent dry cough, Shortness of breath, Chest pain, Wheezing. Skin symptoms: Reddish bumps or patches (especially on the shins, called erythema nodosum), Lupus pernio (purple discoloration on the nose, cheeks, ears). Eye symptoms: Blurred vision, Eye pain or redness, Light sensitivity. Other: Swollen lymph nodes, Joint pain, Irregular heartbeat or heart failure, Neurological symptoms (rare).

Exact cause is unknown, but believed to result from an overactive immune response triggered by environmental exposures (e.g., dust, mold, chemicals), infections (e.g., mycobacteria or viruses), or genetic predisposition. It is not contagious.

No single test to diagnose sarcoidosis. Often a diagnosis of exclusion: Chest X-ray or CT scan (shows granulomas or lymph node enlargement); Lung function tests; Biopsy of affected tissue showing granulomas; Blood tests (may show elevated ACE levels, calcium, or inflammation); Eye and heart exams.

Many people with sarcoidosis do not need treatment if symptoms are mild and organs are not impaired. If treatment is needed: Corticosteroids (e.g., prednisone) - first-line treatment; Immunosuppressive drugs - methotrexate, azathioprine, hydroxychloroquine; Biologics (e.g., infliximab) in resistant cases; Organ-specific care.

About 50-70% recover without lasting problems. Some people have chronic or relapsing symptoms. Can lead to permanent lung damage, blindness, heart failure, or nerve injury if severe or untreated. Better prognosis in people with acute, limited disease.

Affects about 10 to 40 per 100,000 people in the U.S. More common in African Americans and Northern Europeans. Usually appears between ages 20 and 40. Slightly more common in women.