Retrospective study of 61 patients with adult-onset Still's disease admitted with fever of unknown origin in China.

Adult-onset Still's disease (AOSD), as a category of connective tissue diseases, has about 5∼9% of fever of unknown origin (FUO) cases. Diagnosis of AOSD was challenging because of its nonspecific characteristics. The present study analyzed clinical manifestations and laboratory findings in a series of patients with AOSD from eastern China. Medical records of 61 patients admitted with FUO and with a discharge diagnosis of AOSD were retrospectively evaluated and analyzed with special focus on clinical manifestations and laboratory findings. Compared with previous reports, most features of our patients had a similar incidence rate. Rash (79%), arthralgia (80%), and sore throat (84%) were the most frequent clinical manifestations in our series. Leukocytosis (80%), elevated ESR (98%) and CRP (100%), negative ANA (90%) and RF (93%), and high ferritin level (94%) were the most sensitive laboratory findings in our patients. AOSD was not a rare reason of FUO in eastern China. Fever, arthralgia, rash, sore throat, leukocytosis, neutrophilia, elevated ESR and CRP, negative ANA and RF, and high ferritin level were the most common clinical features in our series. The lack of highly specific characteristic makes the diagnosis of AOSD difficult compared with other diseases in FUO.