[Adult Still's disease. A great simulator. Retrospective review of 20 patients].

Background: Adult Still's disease is an inflammatory disorder characterized by quotidian fevers, and an evanescent rash. Its presentation can be acute or subacute.

Aim: To report our experience with Adult Still's disease.

Material And Methods: Systematic retrospective review of medical records of nine men and 11 women aged between 17 and 57 years, with Still's disease, followed in two public hospitals of Metropolitan Santiago.

Results: Eighty percent of patients had a prior different diagnosis. All presented with fever and joint involvement. Eighty percent had malaise, 80% had odynophagia, 80% had an evanescent rash, 70% had myalgias, 50% had lymph node enlargement and 40% had splenomegaly. Laboratory showed leukocytosis in 80% and a high erythrocyte sedimentation rate in all. High ferritin levels were detected in 80%, and became an important diagnosis clue. Initial treatment was based on non steroidal antiinflammatory drugs, however 80% required steroids and 35% required methotrexate. Azathioprine, sulphalazine, hydroxychloroquine and leflunomide were used occasionally. Eleven patients had a single episode, nine had a relapsing disease and four had a chronic or persistent mode.

Conclusions: Adult Still's disease must be suspected in patients with fever of unknown origin. An early diagnosis and adequate treatment of the disease are associated with a favorable evolution and prognosis.