Table 18.1-1. Yamaguchi diagnostic criteria for adult-onset Still disease
Major criteria

1) Fever ≥39°C persisting for ≥1 week

2) Arthralgia/arthritis persisting for ≥2 weeks

3) Typical rash

4) White blood cell count ≥10×109/L (>80% neutrophils)

Minor criteria

1) Sore throat

2) Lymphadenopathy and/or splenomegaly

3) Increased serum aminotransferase or lactate dehydrogenase levels (after other causes have been excluded)

4) Negative IgM rheumatoid factor and antinuclear antibodies (immunofluorescence assay)

Exclusion criteria

1) Infections, in particular sepsis and infectious mononucleosis

2) Malignancy, in particular lymphoma

3) Other rheumatic diseases, in particular polyarteritis nodosa and vasculitis in the course of rheumatoid arthritis

For the diagnosis of adult-onset Still disease, ≥5 criteria must be met, including ≥2 major. In patients with any of the exclusion criteria, the diagnosis is excluded.

Sensitivity of the criteria is 80.6%, and specificity is 98.5%.

Source: J Rheumatol. 1992;19(3):424-30.

Notes: An alternative diagnostic score by Fautrel, without exclusion criteria, is available at www.journals.lww.com. According to this scale, ≥4 major criteria must be met for adult-onset Still disease to be considered (spiking fever of ≥39 degrees Celsius, arthralgia, transient erythema, pharyngitis, polymorphonuclear neutrophil count of ≥80%, glycosylated ferritin of <20%); or 3 major and 2 minor criteria (maculopapular rash and white blood cell count of ≥10×109/L).