Adult-onset Still's Disease (AOSD)

Adult-onset Still's disease (AOSD) is a rare auto-inflammatory condition, meaning that the immune system is overactive. The symptoms usually begin in adulthood. They may include persistent fever, joint pain, and a rash. Other parts of the body may also be affected. Diagnosis is based on medical history, a physical exam, and blood tests. Some further tests may be needed to rule out the presence of similar conditions. Treatment often consists of medications to calm the immune system. With treatment, a complete recovery is possible. However, the condition may come back. Severe complications are very rare.

The exact cause of this condition is unknown, and there are no known risk factors.

Symptoms include a high fever, sore throat, skin rash, and joint and muscle pains. Belly pain and swelling of the lymph nodes, which are small glands throughout the body, may also occur.

Diagnosis is often based on medical history, a physical exam, and blood tests. Further tests might help to rule out other causes for the symptoms.

Treatment aims for a full recovery. It often consists of medication to calm the immune system. Steroids may be used for this in the short term. However, if long-term treatment is needed, different medication may be used.

The outlook for people with AOSD is good and many recover well with treatment. However, the condition can reappear. In very rare cases, there may be life-threatening complications.