sarcoidose

Sarcoidose, or sarcoidosis, is a multisystem inflammatory disease defined by noncaseating granulomas in affected tissues. The cause is unknown, but it is thought to result from an abnormal immune response to environmental or infectious triggers in genetically predisposed individuals. The lungs and mediastinal lymph nodes are most commonly involved.

Epidemiology varies by region and ethnicity. It most often presents in adults aged 20–40 and affects both sexes, with higher incidence in some populations of African descent. Many cases are mild or self-limited, while others progress to organ involvement.

Clinical features range from asymptomatic disease detected on imaging to respiratory symptoms such as cough and dyspnea, chest discomfort, and fatigue. Extras are common, including skin lesions (erythema nodosum, lupus pernio), eye inflammation, arthritis, and sometimes liver, heart, or nervous system involvement. Löfgren syndrome is an acute, often favorable presentation.

Diagnosis relies on compatible clinical findings and radiology, plus histology showing noncaseating granulomas. Infections (t tuberculosis, fungal diseases) and other causes must be excluded. Imaging often shows bilateral hilar lymphadenopathy; biopsy from lung, lymph node, or skin confirms the diagnosis. Serum ACE is supportive but not diagnostic.

Management depends on organ involvement and symptoms. Many cases do not require therapy. When treatment is needed, glucocorticoids are first-line, with gradual taper. Steroid-sparing agents such as methotrexate, azathioprine, or mycophenolate may be used for chronic disease or intolerance. Refractory cases may require biologics such as TNF inhibitors. Regular follow-up monitors progression and organ function.

Prognosis is generally favorable, with spontaneous remission in a substantial subset. Chronic disease or organ damage, especially to the lungs or heart, can occur. Long-term surveillance is advised to detect complications.