Clinical Application Of Revised Definition Of Fever Of Unkown Origin

Background: Fever is a nonspecific symptom in various diseases,prolonged febrile illnesses are diagnostic challenge for the clinician. Thefirst formal definition of FUO (fever of unkown origin) was published in1961:“fever higher than38.3℃(101℉) on several occasions, persistingwithout diagnosis for at least3weeks in spite of at least1week’sinvestigation in hospital”. The concept of FUO provides an efficient strategyfor the clinician to diagnosis and treat the patients with prolonged febrileillnesses. The ongoing expansion of the diagnostic armamentarium andepidemiological changes warrant an change of the spectrum of febrileillnesses, for this reason some searchers have proposed the suggestions toupdate the definition of FUO. In1998, Chinese searchers proposed a newrevised definition of FUO based on the classical definition to combine thedomestic situation:“fever persisting at least2~3weeks and above38.5℃on several occasions, diagnosis cann’t be established after history collecting,physical examination and conventional auxiliary examination”. At present,both of above-mentioned definitions are used in the domestic literatures. The first two criteria of both of above-mentioned definitions allowelimination of most frequently, self-limited, acute viral diseases. The thirdcriterion is allow to patients to complete all the necessary examination. Themain difference between Chinese revised definition and classica definitionis that the duration of fever is decreased from3week to2week, this isorder to more difficult cases are selected in FUO earlier. But thismodulation may significantly change the spectrum of FUO, numbers ofacute viral diseases may be included, and the medical resources are wasted.In our study, we categorized the febrile illness in two groups according tothe revised and classical definition, observe and compare the two groups ofgeneral condition, etiology, data of diagnosis and diagnosis method todiscuss the FUO definition which can reflect the actual situation of thisregion.Objective:1. The aim of our study is to explore the suitable FUOcriterion which reflect the actual situation of this region.2. Investigate theetiology, clinical feature of patients with FUO in this region, estimate theclinical value of the diagnosis workup of FUO.Method:1. Prospective analysis the140patients with who wereadmitted in our hospital between September2010and June2012becauseof prolonged febrile illnesses without diagnosis, categorize them in twogroups according to the duration of fever and the necessary length ofhospital investigation, A group: fever persisting at between2and3weeks, and the diagnosis remained uncertain after3outpatient visits or at least3days of hospital investigation; B group: fever persisting at more than3weeks, and no established diagnosis after1week of hospital investigation.Compare the two groups of general condition, etiology, data of diagnosisand diagnosis method.2. Investigate the etiology and its law of structuredevelopment, clinical feature, estimate the clinical value of the diagnosisworkup, serum levels of inflammatory markers in all the patients withFUO.Result:1. There were no statistically significant differences in generalcondition, etiology, date of diagnosis, diagnosis method between the twogroups.2. Out of the140cases, the most common causes of FUO wereinfectious diseases in the definite diagnosis which account for32%of totalpatients, neoplastic diseases, non-infectious inflammatory diseases andother miscellaneous diseases account for9%,13%,10%, respectively.36%of the patients remained origin unkown until they were discharged fromhospital or death. The proportion of infectious diseases and neoplasticdiseases has declined than in the past, the proportion of non-infectiousinflammatory diseases and other miscellaneous diseases has rised, reversely.The average time of diagnosis is11.4days. Chest and abdomen CT scan,bone marrow smear, tissue biotsy show a low sensitivity and highspecificity in FUO. The serum levels of inflammatory markers such asWBC count,erythrocyte sedimentation rate, C-reactive protein, procalcition show a degree of difference in different kinds of etiology in FUO.Conclusion:1. Chinese revised FUO definition in1998is suitable forthe clinical practice in this region.2. Infections, neoplasms, non-infectiousinflammatory diseases are the main etiological factor in FUO. The etiologyspectrum of FUO and its variation tendency in the past20years are similarwith the other literatures, at home and abroad.3. Chest and abdomen CTscan, bone marrow smear, tissue biotsy have positive value for thediagnosis of FUO.4. The serum levels of inflammatory markers show adegree of difference in different kinds of etiology in FUO, more research isneeded to estimate their diagnostic value.