[Self-limited idiopathic fever. A study of twenty cases (author's transl)].

Out of 23 cases with a final diagnosis of idiopathic fever, 20 had self-limited fever with complete resolution. Comparing the cases of self-limited fever with other groups of patients with fever of unknown origin, the following differences were apparent: compared with tumoral and collagen diseases, self-limited fever occurred more frequently below age 40, the difference being significant (p less than 0.01). Chills occurred more frequently in self-limited fever than in tumoral and collagen diseases, while the incidence was similar in infectious diseases. Infectious, tumoral and collagen diseases presented with significantly greater weight loss (p less than 0.01) than self-limited fever. A greater incidence of hepatosplenomegaly was noted in self-limited fever than in infectious diseases. Hemoglobin and erythrocyte sedimentation rate (ESR) were significantly higher in self-limited fever than in the other illnesses. The NBT test was positive, with a reduction superior to 30% in the six cases in whom it was performed. In nine cases various invasive procedures were utilized: radiology, biopsy, laparoscopy (two cases), and laparotomy (one case). The data on the present series of self-limited idiopathic fever support an infectious origin of the disease because of the following: absence of an age difference with the group with a demonstrated infectious cause; fever of less than two months duration in most cases; presence of chills and less incidence of weight loss, anemia, and elevated ESR in relation to the other groups of fever of unknown origin; a positive NBT test; and spontaneous evolution to complete resolution of the disease.