Fever-of-unknown-origin.docx

Fever of unknown originFrom Wikipedia, the free encyclopediaJump to: navigation, searchFever of unknown originClassification and external resourcesICD-10R50ICD-9780.6MedlinePlus003090MeSHD005335Fever of unknown origin (FUO), pyrexia of unknown origin (PUO) or febris e causa ignota (febris E.C.L) refers to a condition in which the patient has an elevated temperature but despite investigations by a physician no explanation has been found.[1JL2I1'JL-JL5JIf the cause is found it usually is a diagnosis of exclusion, that is, by eliminating all possibilities until only one explanation remains, and taking this as the correct one.Contents• 1 Definition1.1 Classic FUOo 1.2 Nosocomial1.3 Immune-deficiento 1.4 Human immunodeficiency virus (HlV)-associatcd• 2 Some imDortant causes• 3 Diagnosis• 4 Therapy• 5 Prognosis• 6 References[edit] DefinitionIn 1961 Petersdorf and Beeson suggested the following crileria:l，ll2J• Fever higher than 38.3℃ (101 °F) on several occasions• Persisting without diagnosis for al least 3 weeks• At least 1 week's investigation in hospitalA new definition which includes the outpatient setting (which reflects current medical practice) is broader, stipulating:• 3 outpatient visits or• 3 days in the hospital without elucidation of a cause or• 1 week of "intelligent and invasive" ambulatory investigation.国Presently FUO cases are codified in four subclasses.[edit] Classic FUOThis refers to the original classification by Petersdorf and Beeson. Studies show there are five categories of conditions:• infections (e.g. abscesses, endocarditis, tuberculosis, and complicated urinary tract infections),• neoplasms (e.g. lymphomas, leukaemias).• connective tissue diseases (e.g. temporal arteritis and polymyalgia rheumatica, Still's disease, systemic lupus erythematosus, and rheumatoid arthritis),• miscellaneous disorders (e.g. alcoholic hepatitis, granulomatous conditions), and• undiagnosed conditions.山国[edit] NosocomialNosocomial FUO refers to pyrexia in patients that have been admitted lo hospital for at leasl 24 hours. This is commonly related to hospital associated factors such as, surgery, use of urinary catheter, intravascular devices (i.e. "drip", pulmonary arlery calheler), drugs (antibiotics induced Clostridiiun difficile colitis, and drug fever), immobilization (decubitus ulcers). Sicusilis in the inlensive care unil is associated with nasogastric and orotracheal tubes.11112J131 Other conditions that should be considered are deep-vein thrombophlebitis, and pulmonary embolism, Iransfusiov reactions, acalculous cholecyslilis, ihyroiditis, alcohol/drug withdrawal, adrenal insufficiency, pancreatitis.1^[edit] Immune-deficientImmunodeficiency can be seen in patients receiving chemolherapy or in hematologic malignancies. Fever is concommittent with neutroDenia (neutrophil <5()()/uL) or impaired cell-mediated immunity. The lack of immune response masks a potentially dangerous course. Infection is the most common cause.111121131[edit] Human immunodeficiency virus (HlV)-associatedFurther information: Human immunodeficiency viiusHIV-infectcd patients are a subgroup of the immunodeficient FUO, and frequently have fever. The primary phase shows fever since it has a mononucleosis-like illness. In advanced stages of infection fever mostly is the result of a superimposed infections.[edit] Some important causesExtrapulmonary tuberculosis is the most frequent cause of FUO.⑶ Drug・induced hyperthermia, as sole symptom of an adverse reaction to medication, should always be considered. Disseminated granulomatoses such as Tuberculosis, Hisloplasmosis, Coccidioidomycosis, Blastomycosis and Sarcoidosis are associated with FUO. Lymphomas are the most common cause of FUO in adults. Thromboembolic disease (i.e. pulmonaryembolism, deep venous thrombosis) occasionally shows fever. Although infrequent, its potentially lethal consequences warrant evaluation of this cause. Endocarditis, although uncommon, is another important etiology to consider. An underestimated reason is factitious fever. Patients frequently are women that work, or have worked, in the medical field and have complex medical histories.11^[edit] DiagnosisA comprehensive and meticulous history (i.e. illness of family members, recent visit to the tropics, medication), repeated physical examination (i.e. skin rash, eschar, lymphadenopathy, heart muirnur) and myriad laboratory tests (serological, blood culture, immunological) are the cornerstone of finding the cause」“⑶Other investigations may be needed. Ultrasound may show cholelithiasis, echocardiography may be needed in suspected endocarditis and a CT-scan may show infection or malignancy of internal organs. Another technique is Gallium-67 scanning which seems to visualize chronic infections more effectively. Invasive lechniques (biopsy and laparotomy for pathological and bacteriological examination) may be required before a definite diagnosis is possi。