Fever of Unknown Origin: A Review of 20 Patients with Adult-Onset Still’s Disease

In this study we aimed to investigate the followings in the patients with adult-onset Still’s disease (AOSD), admitted and followed as fever of unknown origin (FUO) during the last 18 years in our unit: 1. The rate of them to all the patients with FUO during the same period, 2. Clinical features, 3. Predicting factors of the diagnosis of AOSD in FUO. The number and the etiology of the patients with FUO between 1984 to 2001 and also clinical features of those with AOSD were investigated from the patients’ files. The diagnosis of AOSD was re-analyzed according to the diagnostic criteria of Cush et al. The presumed diagnoses before establishing AOSD and antibiotics used were also noted. Chi-square and Fisher’s exact tests were used for statistical analysis. We determined 130 patients with the diagnosis of FUO and 36 (28%) had collagen vascular diseases. Twenty out of these 36 patients (56%, 12 female, 8 male, mean age: 34 years, range:16-65) had AOSD. Clinical and laboratory findings were as follows: Fever (100%), arthralgia (90%), rash (85%), sore throat (75%), arthritis (65%), myalgia (60%), splenomegaly (40%), hepatomegaly (25%), lymphadenopathy (15%), anemia (65%), neutrophilic leukocytosis (90%), accelerated erythrocyte sedimentation rate (100%), hypertransaminazemia (65%), negative RF (100%), and negative ANA (80%). Antibiotics had been prescribed in 18 (90%) of the patients. The presumed infectious diagnoses were streptococcal tonsilitis/pharyngitis (50%), infective endocarditis (4 patients), sepsis (2 patients), and acute meningitis syndrome (2 patients). The presumed non-infectious diagnoses were acute rheumatic fever (3 patients), seronegative rheumatoid arthritis (2 patients), and polymyositis (2 patients). Sixteen of our patients were followed for a mean duration of 30 months (range: 2-59). A remission was obtained by indomethacine in three (19%) and prednisolone in the remaining. Relapse was detected in three (19%) of these patients. AOSD is one of the most frequent etiologies of FUO. During the diagnostic course of a patient with FUO, a maculopapular rash and/or arthralgia and/or sore throat should raise the suspicion of AOSD. Since the disease had a heterogeneous clinical findings, certain bacterial infections (e.g. streptococcal pharyngitis and sepsis) are generally considered and prescribing antibiotic is a frequent event.