Adult-onset Stillís disease is a rare, inflammatory form of arthritis, which affects joints, tissues, lymph nodes, and internal organs. In 1971, Bywaters described a condition in adults, which resembled Stillís disease in children, and termed it adult-onset Stillís disease (AOSD).
The disease is rare, and occurs at a frequency of 1 in 10 000. It bears a few similarities to juvenile rheumatoid arthritis but is observed only in adults. Adults in the age range of 15 to 25, and 39 to 45 years, are often affected by AOSD. Older adults, over the age of 70 years, may also show initial symptoms of AOSD. Some of the characteristic symptoms of AOSD are pink rash, sore throat, high fever, and onset of joint pain in the space of 2 weeks.
The exact cause of AOSD is unknown. The various possibilities are a reaction to an infection with a virus (eg, hepatitis B, hepatitis C, Epstein-Barr, influenza, rubella, cytomegalovirus, among others), or bacterium (M.pneumonia, Yersinia entercolitica). Another factor is the genetic predisposition of individuals to the disease. High stress in daily life has also been shown to be a predisposing factor inAOSD.
Diagnosis of AOSD is based on blood tests and imaging studies. It is treated with NSAIDs or anti-inflammatory drugs like glucocorticoids, methotrexate or newer drugs like anakinra and etanercept.