Adult Onset Still's Disease: A Retrospective, Single-Center Study

Background Adult-onset Still's disease (AOSD) is characterized by a classical triad of spiking fever, arthritis, and evanescent rash. It is one of the main causes of hospital admissions for fever of unknown origin and has an extended mean time to diagnosis. Therefore, it remains underdiagnosed relative to its aforementioned time frame. In this study, we attempt to highlight clinical and lab findings associated with AOSD. We then compare our diagnostic results with similar previous studies. Our results should help physicians not to miss this rare entity and make the diagnosis in a reduced time frame. Materials and methods This a retrospective, single-center study conducted at Dow University Hospital in Karachi, Pakistan. Thirty patients were enrolled in this study for six months (July 2019-December 2019). All patients were identified and recruited in the medical outpatient department using Yamaguchi's criteria. Written consent was obtained from all patients to access all their clinical charts. Demographics and prior results of laboratory investigations were retrieved from the chart files. Results In our study, the mean age of patients was 26.6 years. More specifically, males accounted for 53.3% (n=16) of cases, and females accounted for 46.6% (n=14) of total cases. The most common presenting clinical features included arthralgia (100%, n=30), fever (100%, n=30), myalgia (96.6%, n=29), large joint arthritis (66.6%, n=20), sore throat (50%, n=15), hepatomegaly (40%, n=12), splenomegaly (23.3%, n=7), skin rash (36.6%, n=11) and pericarditis (20%, n=6). Furthermore, none of our patients had cervical lymphadenopathy. The most commonly reported laboratory findings include leukocytosis (100%, n=30), hyperferritinemia (90%, n=27), elevated erythrocyte sedimentation rate (100%, n=30) and abnormal liver function tests (76.6%, n=23). Chest x-rays performed in all patients revealed no abnormalities in 83% of patients (n=25). All patients in our study sample (n=30) tested negative for antinuclear antibodies and rheumatoid factor. It was also noted that the mean duration of diagnosis in our patients was 5.98 weeks. The mean hospitalization period in our patients was 12.5 days. Furthermore, 16.7% of patients (n=5) suffered from disease relapse.  Conclusion Our study ascertains that the presence of certain clinical and laboratory findings strongly indicate a diagnosis of adult-onset Still's disease.