50-year-old male was diagnosed with Juvenile arthritis with systemic onset (Stills disease) after having symptoms of high fever, rashes and pain. He was treated with high doses of corticosteroids, but had two exacerbations in the last 2 years. In the current time he suffers of swelling of knee joints and hand joints, and occasionally a feeling of burning feet or cold feet. In the expert's opinion, the clinical description fit well with the diagnosis of adult onset systemic arthritis which manifestations are similar to the juvenile systemic arthritis.