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Still disease is a systemic form of juvenile chronic arthritis in which high spiking fevers are much more prominent, especially at the outset, than arthritis. This extremely rare syndrome also occurs in adults. Most adults are in their 20s or 30s; onset after age 60 is rare. The fever is dramatic, often with daily spikes to 40°C, associated with sweats and chills, and then plunging to normal or several degrees below normal in the absence of antipyretics. Many patients initially complain of sore throat. An evanescent salmon-colored nonpruritic rash, chiefly on the chest and abdomen, is a characteristic feature. The rash can easily be missed since it often appears only with the fever spike. Many patients have lymphadenopathy and pericardial effusions. Joint symptoms are mild or absent initially, but a destructive arthritis, especially of the wrists, may develop months later. Liver enzyme elevations occur in most patients. Anemia and leukocytosis (predominantly neutrophilia), with peripheral WBC counts often exceeding 15,000/mcL (15 × 109/L), are the rule. Serum ferritin levels are often strikingly elevated (greater than 3000 mg/mL or 6741 pmol/L). (Other conditions, including viral infections, malignancy, and multiple blood transfusions, can also cause extreme elevations in ferritin levels.) A low percentage (less than 20%) of serum ferritin that is glycosylated may be even more specific for adult Still disease. The diagnosis of adult Still disease is suggested by the quotidian fever pattern, sore throat, and the classic rash, but it requires exclusion of other causes of fever. About 20% of patients with mild disease respond to NSAIDs. Many patients require prednisone, sometimes in doses greater than 60 mg/day orally. Targeting IL-1 (anakinra or canakinumab), IL-6 (tocilizumab), or TNF (infliximab, etanercept, or adalimumab) can be effective for patients with refractory disease. The course of adult Still disease can be monophasic, intermittent, or chronic. Intermittent adult Still disease must be distinguished from other causes of periodic fever syndromes, including familial Mediterranean fever, TNF receptor-1 associated periodic syndrome (TRAPs), and Schnitzler syndrome (intermittent bone pain, urticarial rash, and fever associated with a monoclonal gammopathy).
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Macrophage activation syndrome is a serious, potentially life-threatening complication of Still disease. It manifests as fever; splenomegaly; cytopenia; liver dysfunction; hypertriglyceridemia; hypofibrinogenemia; marked ferritin elevation; elevated soluble CD25; depressed natural cell activity; and hemophagocytosis in bone marrow, spleen, and lymph nodes.
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Fautrel
B
et al. Systematic review on the use of biologics in adult-onset Still's disease. Semin Arthritis Rheum. 2022;58:152139.
[PubMed: 36442231]
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Giacomelli
R
et al; Expert Panel. Expert consensus on the treatment of patients with adult-onset Still's disease with the goal of achieving an early and long-term remission. Autoimmun Rev. 2023;22:103400.
[PubMed: 37482365]
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Kedor
C
et al. Canakinumab for Treatment of Adult-Onset Still's Disease to Achieve Reduction of Arthritic Manifestation (CONSIDER): phase II, randomised, double-blind, placebo-controlled, multicentre, investigator-initiated trial. Ann Rheum Dis. 2020;79:1090.
[PubMed: 32404342]