You are a helpful, respectful, and honest assistant. Always answer as helpfully as possible, while being safe. Your answers should not include any harmful, unethical, racist, sexist, toxic, dangerous, or illegal content. Please ensure that your responses are socially unbiased and positive in nature. If a question does not make any sense or is not factually coherent, explain why instead of answering something not correct. If you don't know the answer to a question, please don't share false information.
What is True about Sarcoidosis is? and explain in detail?
Ans. is 'c' i.e., Non caseating granulomas Sarcoidosis* Sarcoidosis is an immune system disorder characterized by the presence of non-caseating granulomas (aggregate of tightly clustered epitheloid cells, often with langhans or forein body type giant cells. Central necrosis is unusual)* Granulomas most often appear in the lung or the lymph nodes --> Bilateral hilar lymphadenopathy or lung involvement is visible on chest radiograph in 90% of cases.* Granulomas also contain:-A. Schaumann bodies - Laminated concretions composed of calcium and proteins.B. Asteroid bodies - Stellate inclusions within giant cells.Clinical features1. Lung and lymph nodes (95%)* Respiratory complaints including cough and dysnea are the most common presenting symptoms. Usually the infiltrate in sarcoidosis are predominantly an upper lobe process. There is bilateral hilar lymphadenopathy.* 'Potato nodes' are seen in sarcoidosis.2. Skin (24%-43%)* Skin lesions include erythma nodosum, maculopapular lesion, subcutaneous nodules, hypo or hyperpigmentation, keloid formation and lupus pernio.* Lupus pernio is involvement of bridge of nose, area beneath the eyes and cheek. It is diagnostic for a chronic form of sarcoidosis.3. Eye (12-29%)* Eye lesions include uveitis, retinitis, pars planitis and dry eye due to lacrimal gland involvement.* Uveoparotid fever (Heerfordt-Waldenstrome syndrome) include classical triad of Uveitis, parotitisand 7th nerve palsy.4. Other organs involved* These are salivary glands particulary parotid (causing dry mouth), spleen (splenomegaly), liver, heart and brain (neurosarcoidosis). Granuloma in sarcoidosis can secrete 1-25 (OH)2 vitamin-D which causes hypercalcemia.