Arthritis with or preceding daily fever with a duration of at least two weeks accompanied by at least one of the following symptoms during the first six months.

– Erythematous rash;

– Lymphadenopathy;

– Hepatomegaly and/or splenomegaly;

– Serositis.

Exclusion criteria

– Psoriasis or history of psoriasis in the patient or first degree relative;

– Arthritis in a boy (six year-old or more) positive for HLA-B27;

– Ankylosing spondylitis, enthesitis with arthritis, sacroiliitis and inflammatory bowel disease, Reiter syndrome or acute anterior uveitis in a first degree relative;

– Presence of rheumatoid factor type IgM confirmed in an interval of at least three months apart.