Idiopathic granulomatosis manifesting as fever of unknown origin

Twenty patients with fever of unknown origin were found to have idiopathic granulomatosis of the liver, lymph nodes, spleen, or bone marrow. At the time of initial examination, these patients had persistent or recurrent fever and pronounced constitutional symptoms but few physical findings. The most common laboratory abnormalities were increased erythrocyte sedimentation rate in 18, abnormal results of liver function tests in 12, anemia in 11, and hypergammaglobulinemia in 10. Of the 20 patients, 14 required corticosteroids at the beginning of the illness for control of symptoms, especially fever. After 5 to 10 years of follow-up, an alternative diagnosis had been established in 5 of the 20 patients. Of the remaining 15 patients with fever and idiopathic granulomatosis, 6 are still receiving corticosteroids. Corticosteroid treatment did not result in progression or dissemination of an unrecognized infection. No clinical or laboratory abnormality helped to predict the need for long-term corticosteroid treatment.