Definition:

Adult-onset Still disease (AOSD) is a systemic inflammatory disorder. The disease manifestations are protean ranging from high fever, arthralgia, skin rash, sore throat, lymphadenopathy, and hepatosplenomegaly accompanied by systemic manifestations. Complications of AOSD include transient pulmonary hypertension, macrophage activation syndrome, diffuse alveolar hemorrhage, thrombotic thrombocytopenic purpura and amyloidosis. Common laboratory abnormalities include neutrophilic leukocytosis, abnormal liver function tests, and elevated acute-phase reactants (ESR, CRP, ferritin). The exact pathogenesis of AOSD is unknown. Several factors such as genetics, infectious (bacterial and viral) agents, and environmental factors have been thought to play a causative role. Although no familial trend has been reported in AOSD, some studies have reported an association between AOSD and gene polymorphism of HLA, IL-18, and MEFV. Recent advances have revealed a pivotal role of proinflammatory cytokines such as TNF-alpha, IL-1, IL-6, IL-8, and IL-18 in disease pathogenesis. Treatment consists of anti-inflammatory medications. Non-steroidal anti-inflammatory drugs have limited efficacy, and corticosteroid therapy and disease-modifying anti-rheumatic drugs are usually required.