sarcoidosis

Sarcoidosis is a condition in which the immune system, for reasons not fully understood, forms tiny clusters of inflammatory cells called granulomas in various organs. Imagine the body raising lots of little roadblocks in tissue where there is no clear invader to fight. The lungs and the lymph nodes inside the chest are by far the most commonly affected sites.

Many people with sarcoidosis have few or no symptoms, and the disease is sometimes found by chance on a chest X-ray showing enlarged hilar lymph nodes. Others develop cough, breathlessness, fatigue, eye inflammation, skin lesions, or, less commonly, problems with the heart or nervous system. Its behaviour ranges from mild and self-limiting to chronic and disabling.

Diagnosis usually combines a compatible clinical and imaging picture with tissue showing non-caseating granulomas, while carefully excluding infections such as tuberculosis and other granulomatous diseases. Because there is no single definitive test, sarcoidosis is in part a diagnosis of exclusion supported by biopsy.

A reassuring feature is that many cases resolve without treatment. When organs are threatened or symptoms are significant, corticosteroids are the usual first-line therapy, with other immune-suppressing drugs added if needed. A minority progress to pulmonary fibrosis, which is why long-term follow-up matters.