Fever of unknown origin

What Is Fever of Unknown Origin in Cats? Just like humans, cats can run a higher-than-normal body temperature when they are ill. This has many causes. A cat’s normal body temperature is between 100 F and 102.5 F. A typical fever in a cat is considered a symptom until further diagnosis can confirm what illness is causing it. However, fever of unknown origin is a medical condition that will also need to be determined through diagnosis. Fever in cats may be due to: • Excitement • Anxiousness • Pain • Sickness An anxious, but otherwise healthy, cat with a 103 F temperature may not be considered feverish. On the other hand, a quiet and lethargic cat that has a 103 F temperature and shows other symptoms of illness may be considered feverish. A veterinarian usually interprets your cat’s body temperature by: • Performing a thorough physical exam • Examining your cat’s medical history Symptoms of Fever of Unknown Origin in Cats When your cat has a fever, they may: • Feel lethargic • Sleep more than usual • Have no appetite • Hide • Avoid normally enjoyed activities • Vomit • Have diarrhea If any of these symptoms occur, you should call your veterinarian for an appointment. Causes of Fever of Unknown Origin in Cats Persistent fevers that last more than a day may be caused by infection, inflammation, and pain. You may suspect a fever if your cat feels warmer to the touch than usual. This can be confirmed at home with a rectal or ear thermometer. Some fevers in cats have clearly ident...

Fever of unknown origin (FUO) in adults is defined as a temperature higher than 38.3 C (100.9 F) that lasts for more than three weeks with no obvious source despite appropriate investigation. The four categories of potential etiology of FUO are classic, nosocomial, immune deficient, and human immunodeficiency virus–related. The four subgroups of the differential diagnosis of FUO are infections, malignancies, autoimmune conditions, and miscellaneous. A thorough history, physical examination, and standard laboratory testing remain the basis of the initial evaluation of the patient with FUO. Newer diagnostic modalities, including updated serology, viral cultures, computed tomography, and magnetic resonance imaging, have important roles in the assessment of these patients. Category of FUO Definition Common etiologies Classic Temperature >38.3°C (100.9°F) Infection, malignancy, collagen vascular disease Duration of >3 weeks Evaluation of at least 3 outpatient visits or 3 days in hospital Nosocomial Temperature >38.3°C Clostridium difficile enterocolitis, drug-induced, pulmonary embolism, septic thrombophlebitis, sinusitis Patient hospitalized ≥24 hours but no fever or incubating on admission Evaluation of at least 3 days Immune deficient (neutropenic) Temperature >38.3°C Opportunistic bacterial infections, aspergillosis, candidiasis, herpes virus Neutrophil count ≤ 500 per mm 3 Evaluation of at least 3 days HIV-associated Temperature >38.3°C Cytomegalovirus, Mycobacterium avium...

Continuing Education Activity Fever of unknown origin (FUO) was first described by Dr. Petersdorf and Dr. Beesom in 1961. FUO was defined as a temperature of 101 degrees Fahrenheit (38.3 degrees Centigrade) or higher with a minimum duration of three weeks without an established diagnosis after an intensive one-week investigation in the hospital. Today, due to technological advances allowing for sophisticated outpatient evaluations, the one-week inpatient investigation is no longer required. This activity reviews the cause and presentation of fever of unknown origin and highlights the role of the interprofessional team in its management. Objectives: • Describe the workup of a patient with a fever of unknown origin. • Outline the causes for fever of unknown origin. • Summarize the treatment of patients with fever of unknown origin. • Review the importance of improving care coordination among interprofessional team members to improve outcomes for patients affected by fever of unknown origin. Introduction Fever of unknown origin (FUO) was first described by Dr. Petersdorf and Dr. Beesom in 1961. Acomprehensive historyand physical examination can aid in diagnosis and direct diagnostic testing. Recommended investigations for work-up include complete blood count (CBC) with differential, three sets of blood cultures (from different sites, several hours apart, and before initiation of antibiotic therapy, ifindicated), chest radiograph, complete metabolic panel (including hepatitis ...

Abstract Fever has preoccupied physicians since the earliest days of clinical medicine. It has been the subject of scrutiny in recent decades. Historical convention has mostly determined that 37.0°C (98.6°F) should be regarded as normal body temperature, and more modern evidence suggests that fever is a complex physiological response involving the innate immune system and should not be characterized merely as a temperature above this threshold. Fever of unknown origin (FUO) was first defined in 1961 by Petersdorf and Beeson and continues to be a clinical challenge for physicians. Although clinicians may have some understanding of the history of clinical thermometry, how average body temperatures were established, thermoregulation, and pathophysiology of fever, new concepts are emerging. While FUO subgroups and etiologic classifications have remained unchanged since 1991 revisions, the spectrum of diseases, clinical approach to diagnosis, and management are changing. This review considers how newer data should influence both definitions and lingering dogmatic principles. Despite recent advances and newer imaging techniques such as 18-fluorodeoxyglucose–positron emission tomography, clinical judgment remains an essential component of care. Humanity has but three great enemies: fever, famine, and war; of these by far the greatest, by far the most terrible, is fever. William Osler Concepts of fever have changed over the past millennia, dating from the earliest known fever curv...

Diagnosis To evaluate a fever, your care provider may: • Ask questions about your symptoms and medical history • Perform a physical exam • Take nasal or throat samples to test for respiratory infections • Order tests, such as blood tests or a chest X-ray, as needed, based on your medical history and physical exam Because a fever can indicate a serious illness in a young infant, especially two months of age or younger, your baby might be admitted to the hospital for testing and treatment. Fever of unknown origin When a fever lasts for more than three weeks — constantly or on several occasions — and there is no clear cause, it's usually called a fever of unknown origin. In these cases, you may need to see specialists in one or more medical fields for further evaluations and tests. Treatment For a low-grade fever, your care provider may not recommend taking medications to lower your body temperature. These minor fevers may be helpful in reducing the number of microbes causing your illness. Fevers above 102 F (38.9 C) tend to cause discomfort and often require treatment. Over-the-counter medications In the case of a high fever or a fever that causes discomfort, your care provider may recommend nonprescription medication, such as acetaminophen (Tylenol, others) or ibuprofen (Advil, Motrin IB, others). Use these medications according to the label instructions or as recommended by your health care provider. Be careful not to take too much. High doses or long-term use of acetamino...

Even if dogs present with clearly swollen and painful joints, the vet must look at the bigger picture and evaluate the situation in detail which often requires additional tests, including the above-mentioned synovial fluid samples, blood tests, complete blood counts (especially white cell counts), x rays of the joints and other organs, and infectious disease screenings.