Sarcoidosis

Sarcoidosis is an inflammatory condition characterized by the formation of granulomas — small collections of immune cells — in one or more organs, most often the lungs and lymph nodes. Its exact cause is unknown, but it is thought to result from an exaggerated immune response to an environmental, infectious, or other antigenic trigger in a genetically susceptible person. It most commonly affects young and middle-aged adults.

Presentation varies widely with the organs involved. Many cases are mild or found incidentally, while others cause a persistent dry cough, breathlessness, and chest discomfort from lung involvement. General symptoms such as fatigue, fever, night sweats, weight loss, and swollen lymph nodes are common, and skin lesions, eye inflammation, and joint pain may also occur.

Diagnosis is based on a combination of imaging (chest X-ray or CT showing characteristic changes), blood tests (which may show a raised serum ACE level and altered calcium), and biopsy demonstrating non-caseating granulomas while excluding other causes such as infection.

Sarcoidosis can be associated with pulmonary fibrosis and pulmonary hypertension, disturbances of calcium metabolism with kidney stones, eye disease, cardiac and neurological involvement, and an increased burden of fatigue and mood disturbance.