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

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

To report our experience with Adult Still's disease.

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.

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.

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.