Evaluation of adult-onset Still's disease

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disorder characterized by high spiking fever, arthralgia, and rash. In this study, we aimed to retrospectively evaluate the clinical and laboratory characteristics, disease courses, complication frequency, and treatment modalities of patients diagnosed and followed at our institution between 1998 and 2023 according to the Yamaguchi criteria. Of the 91 patients followed, 71 were female and 20 were male. The mean age was 52.39 years, the mean age at diagnosis was 39.71 years, and the mean diagnostic delay was 12.74 months. Fever was observed in 95.6% of patients, rash in 80.2%, sore throat in 48.4%, myalgia in 42.9%, arthralgia in 84.6%, lymphadenopathy in 39.6%, hepatomegaly in 26.4%, and splenomegaly in 13.2%. Regarding disease course, 56% of patients exhibited a monophasic course, 36.3% a polyphasic course, and 7.7% a chronic articular course. No significant association was found between disease course and patients' mean age, age at diagnosis, or diagnostic delay. Similarly, no significant relationship was identified between disease course and clinical manifestations. While no significant association was observed between disease course and laboratory findings at diagnosis, significant associations were identified between disease course and hemoglobin levels, erythrocyte sedimentation rate (ESR), and C-reactive protein (CRP) levels at the last follow-up visit. When the relationship between disease course and first- and second-line treatments was evaluated, significant associations were found between disease course and first-line non-steroidal anti-inflammatory drugs (NSAIDs), second-line corticosteroids, second-line methotrexate, second-line leflunomide, second-line anakinra, and firstline anti–tumor necrosis factor (anti-TNF) therapies. No significant association was found between disease course and the overall occurrence of complications.