[Still's disease in adults. 2 case reports].

Two patients with adult Still's disease are presented. Both had high "septic" fever, weight loss, mild pharyngitis, evanescent maculo-papular rash, myalgias, arthralgias, splenomegaly and pericarditis, while one of the two patients also had lymphadenopathy and pleurisy. Arthritis, which is a sine qua non for the diagnosis, developed only 5 months after disease onset in one patient. Both ultimately developed severe destructive joint disease requiring hip arthroplasty. Laboratory findings were neutrophilic leukocytosis, normochromic normocytic anemia, elevated ESR, slightly elevated liver enzyme values, negative IgM-rheumatoid factor and antinuclear antibodies, and normal or slightly elevated complement factors. Several biopsies failed to reveal pathognomonic findings. It is of the utmost importance that the exclusion diagnosis of adult Still's disease be posed in order to avoid repeated hospitalizations with undue investigations and unnecessary therapeutic trials with antibiotics.