Sarcoidosis is a disorder of the immune system characterized by the appearance of granulomatous nodules, especially on the lungs and lymph nodes. Occasionally, other organs like the eyes, skin, liver, and heart, and other organ systems, such as the musculoskeletal, nervous, and/or endocrine systems may also be affected. Apart from the granulomas, other symptoms of the condition are not definitive, and include vague features like fatigue, weight loss, aches and pains, arthritis, myositis, dyspnea, dry cough, skin lesions (ranging from rashes and noduli to erythema nodosum and lupus pernio), and ocular abnormalities (dry eye, blurry vision, uveitis, retinal inflammation). When other organs are affected, more severe symptoms, like lung scarring, and problems involving the nervous system, heart liver, and fertility, can be expected.
Sarcoidosis shows a very varied incidence among different populations. Among African Americans the disease is 10-17 times more common (35-64/100,000) than in whites. Scandinavians have the highest frequency of this condition in the world, whereas other populations like South East Asians, Native Americans, Eskimos, etc. have a very low incidence of the disease. The disease tends to show itself mostly between the ages of 25 and 35, and 45 and 65 years. Biopsies of affected areas, chest X-rays, lung function tests, bronchoscopy, and slit-lamp examination are some of the preliminary examinations conducted to diagnose the condition in suspected individuals. A lot of times, sarcoidosis tends to go away on its own in two to three years, without the help of medications. Therefore, doctors tend to prescribe a wait and see approach. Only in severe cases, is medication prescribed, which may include glucocoticoids, NSAIDs, and colchicine.
Sarcoidosis has shown familial clustering in some cases. In addition, monozygotic twins are more likely to develop the condition than dizygotic twins. HLA-DRB1 has been found to confer susceptibility to the disease. Other HLA associations include HLA-DPB1 and HLA-DRB3.