Sarcoidosis

Sarcoidosis affects the lungs and lymph nodes most often, and can involve the skin, eyes, heart, liver, or nervous system. The immune system is thought to overreact to an environmental or infectious trigger in a person with a genetic susceptibility, forming tiny clusters of inflammatory cells called granulomas in the affected tissue. It is generally described as immune-mediated rather than classically autoimmune, since it does not center on antibodies attacking the body's own tissue the way lupus does.

Research describes sarcoidosis as having wide variation in incidence by region, race, and sex, and much about its underlying cause remains unclear despite over a century of study. At least 90 percent of people with sarcoidosis show some lung involvement, and the disease can range from a finding on incidental imaging to a serious multi-organ illness.

Common signs

Many people have a persistent dry cough, shortness of breath, or chest discomfort. Others notice fatigue, low fevers, night sweats, swollen lymph nodes, tender reddish bumps on the shins, eye redness or blurred vision, and joint or skin changes. Some have no symptoms at all and it is found on imaging done for another reason, most often as enlarged lymph nodes on a routine chest x-ray.

This is a plain-language summary for orientation, not a diagnosis. Mechanisms are described as current understanding, not settled fact. Work with your own clinician for your care.