Clinical course
Three broad patterns of disease have traditionally been recognized:[5]Efthimiou P, Kontzias A, Hur P, et al. Adult-onset Still's disease in focus: clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies. Semin Arthritis Rheum. 2021 Aug;51(4):858-74.
https://www.doi.org/10.1016/j.semarthrit.2021.06.004
http://www.ncbi.nlm.nih.gov/pubmed/34175791?tool=bestpractice.com
[42]Cush JJ, Medsger TA Jr, Christy WC, et al. Adult-onset Still's disease. Clinical course and outcome. Arthritis Rheum. 1987 Feb;30(2):186-94.
https://www.doi.org/10.1002/art.1780300209
http://www.ncbi.nlm.nih.gov/pubmed/3827959?tool=bestpractice.com
Monocyclic systemic (21% to 64% of cases): typically consists of one episode lasting a few months followed by remission
Polycyclic systemic (9% to 50%): intermittent episodes or flares
Chronic articular (12% to 56%): persisting and progressive symptoms, particularly affecting the joints.
The advent of targeted and biologic agents is likely to have a significant impact on the distribution of these clinical courses. Though chronic and progressive AOSD is the most frequent pattern, more prompt recognition and induction of therapy will allow a large number of these patients to achieve rapid and sustained disease control, bringing parity with the other disease patterns.[91]Feist E, Mitrovic S, Fautrel B. Mechanisms, biomarkers and targets for adult-onset Still's disease. Nat Rev Rheumatol. 2018 Oct;14(10):603-18.
https://www.doi.org/10.1038/s41584-018-0081-x
http://www.ncbi.nlm.nih.gov/pubmed/30218025?tool=bestpractice.com
With all patterns of AOSD there is a high likelihood of rapid response to corticosteroids as well as biologic agents.[74]Galozzi P, Bindoli S, Doria A, et al. Progress in biological therapies for adult-onset Still's disease. Biologics. 2022;16:21-34.
https://www.doi.org/10.2147/BTT.S290329
http://www.ncbi.nlm.nih.gov/pubmed/35481241?tool=bestpractice.com
Nonetheless, observational studies report that many patients require medications for symptom control for months and years, highlighting the heterogeneity of the disease course and the need to take an individual approach with each patient.[5]Efthimiou P, Kontzias A, Hur P, et al. Adult-onset Still's disease in focus: clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies. Semin Arthritis Rheum. 2021 Aug;51(4):858-74.
https://www.doi.org/10.1016/j.semarthrit.2021.06.004
http://www.ncbi.nlm.nih.gov/pubmed/34175791?tool=bestpractice.com
[91]Feist E, Mitrovic S, Fautrel B. Mechanisms, biomarkers and targets for adult-onset Still's disease. Nat Rev Rheumatol. 2018 Oct;14(10):603-18.
https://www.doi.org/10.1038/s41584-018-0081-x
http://www.ncbi.nlm.nih.gov/pubmed/30218025?tool=bestpractice.com
Prognosis
Mortality data for AOSD is scarce and varies widely between studies.[5]Efthimiou P, Kontzias A, Hur P, et al. Adult-onset Still's disease in focus: clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies. Semin Arthritis Rheum. 2021 Aug;51(4):858-74.
https://www.doi.org/10.1016/j.semarthrit.2021.06.004
http://www.ncbi.nlm.nih.gov/pubmed/34175791?tool=bestpractice.com
One 5-year retrospective study of 5820 people hospitalized for ASOD in the US found an inpatient mortality rate of 2.6%.[12]Mehta BY, Ibrahim S, Briggs W, et al. Racial/ethnic variations in morbidity and mortality in adult onset Still's disease: an analysis of national dataset. Semin Arthritis Rheum. 2019 Dec;49(3):469-73.
https://www.doi.org/10.1016/j.semarthrit.2019.04.004
http://www.ncbi.nlm.nih.gov/pubmed/31109638?tool=bestpractice.com
The specific mortality rate has been estimated at 1% to 3%.[4]Macovei LA, Burlui A, Bratoiu I, et al. Adult-onset Still's disease-a complex disease, a challenging treatment. Int J Mol Sci. 2022 Oct 24;23(21):12810.
https://www.doi.org/10.3390/ijms232112810
http://www.ncbi.nlm.nih.gov/pubmed/36361602?tool=bestpractice.com
Evidence suggests that a delay in diagnosis of more than 6 months is associated with an increased likelihood of patients developing relapses or chronic articular patterns of disease.[5]Efthimiou P, Kontzias A, Hur P, et al. Adult-onset Still's disease in focus: clinical manifestations, diagnosis, treatment, and unmet needs in the era of targeted therapies. Semin Arthritis Rheum. 2021 Aug;51(4):858-74.
https://www.doi.org/10.1016/j.semarthrit.2021.06.004
http://www.ncbi.nlm.nih.gov/pubmed/34175791?tool=bestpractice.com