Most common organ involved in sarcoidosis

Sarcoidosis is a multisystem granulomatous disorder of unknown aetiology that is characterised by the presence of non-caseating granulomas . The condition is more frequentlydescribed in colder pas of nohern Europe .The tendency for sarcoid to present in the spring and summer has led to speculation about the role of infective agents, including mycobacteria, propionibacteria and viruses, but the cause remains elusive. Genetic susceptibility is suppoed by familial clustering; a range of class II HLA alleles confer protection from, or susceptibility to, the condition. Sarcoidosis occurs less frequently in smokers. It may be associated with common variable immunodeficiency .Bilateral hilar lymphadenopathy (BHL) is often seen in young women .Alternatively, BHL may be detected in an otherwise asymptomatic individual undergoing a chest X-ray for other purposes. Sarcoidosis is considered with other DPLDs, as over 90% of cases affect the lungs, but the condition can involve almost any organ . Lofgren's syndrome - an acute illness characterised by erythema nodosum, peripheral ahropathy, uveitis, bilateral hilar lymphadenopathy (BHL), lethargy and occasionally fever - is often seen in young women. Alternatively, BHL may be detected in an otherwise asymptomatic individual undergoing a chest X-ray for other purposes. Pulmonary disease may also present in a more insidious manner with cough, exeional breathlessness and radiographic infiltrates; chest auscultation is often surprisingly unremarkable . Ref - Davidsons 23e p630