Objectives: To characterise the clinical phenotype of Italian patients with adult-onset Still's disease (AOSD).
Methods: Sixty-six subjects who received a definite diagnosis of AOSD were seen and followed-up at our institution from 1991 to 2009. The diagnosis was made by a senior rheumatologist and confirmed by Yamaguchi's criteria for AOSD. Data regarding clinical manifestations, laboratory and radiographic features, and disease course were collected and compared with those reported in other published series of different ethnicity.
Results: The most frequent features were: articular pain (100%), acute phase reactants elevation (100%), elevated serum ferritin (97%), high fever (95%), negative RF and ANA (92%), neutrophilia (82%), skin rash (79%), and overt arthritis (79%). Forty-percent of patients showed a chronic articular disease. Five subjects (8%) experienced severe, life-threatening complications, and 1 patient died. As compared to other North American, North European, Middle Eastern, and Far Eastern cohorts, Italian patients showed significant differences in several epidemiologic, clinical and laboratory features.
Conclusions: Our data show that AOSD is rare in the Italian population, and that its clinical presentation appears to be significantly influenced by the ethnicity of the affected patients. Given its broad differential diagnosis, early recognition of this condition is challenging, but it could become crucial in the setting of severe complications. Beyond the protean manifestations of this disease, a clinical picture of seronegative febrile arthritis and skin rash, concurrent with a marked elevation in serum ferritin should always be mindful of AOSD.