Table of Contents

1. Introduction to Fever of Unknown Origin (FUO)
2. Causes of FUO
3. Diagnostic Approaches
4. Management and Treatment Options
5. Hysen Company Solutions
6. Conclusion
7. References

Introduction to Fever of Unknown Origin (FUO)

Fever of Unknown Origin (FUO) is a condition characterized by a fever higher than 38.3°C (101°F) that persists for more than three weeks and remains undiagnosed after three days of in-hospital investigation or after multiple outpatient visits. FUO presents a significant diagnostic challenge due to its diverse etiology.

Causes of FUO

The causes of FUO can be broadly categorized into infections, malignancies, non-infectious inflammatory diseases, and miscellaneous causes. In some cases, the cause remains unidentified even after exhaustive evaluation.

Infections

Infections account for approximately 20%-40% of FUO cases. Common infectious causes include tuberculosis, HIV, endocarditis, and abscesses. Less common causes are systemic fungal infections and atypical bacterial infections.

Malignancies

Malignancies are responsible for 20%-30% of FUO cases, with lymphoma and leukemia being the most common. Solid tumors, especially renal cell carcinoma and hepatic malignancies, can also cause FUO.

Non-Infectious Inflammatory Diseases

This category includes systemic diseases such as rheumatoid arthritis, systemic lupus erythematosus, and giant cell arteritis. They account for 10%-30% of FUO cases.

Miscellaneous Causes

Miscellaneous causes involve drug-induced fevers, factitious fever, and thyroiditis. Despite thorough evaluation, about 10%-15% of FUO cases remain idiopathic.

Diagnostic Approaches

The diagnostic approach to FUO involves a comprehensive evaluation, including a detailed medical history, physical examination, laboratory tests, and imaging studies. Initial laboratory tests should include a complete blood count, erythrocyte sedimentation rate, C-reactive protein, liver function tests, renal function tests, urinalysis, and blood cultures. Imaging studies, such as chest X-rays, abdominal ultrasonography, and computed tomography (CT) scans, are often utilized to identify potential sources of infection or malignancy.

Management and Treatment Options

Management of FUO involves obtaining a precise diagnosis and implementing appropriate treatment. Empirical therapy may be considered in selected cases; however, it should be used cautiously to avoid masking symptoms or delaying accurate diagnosis. The treatment typically targets the underlying cause once identified.

Hysen Company Solutions

Hysen Company provides innovative diagnostic solutions and tools, such as advanced imaging modalities and laboratory systems, to aid in the identification of the underlying causes of FUO. Their technologies focus on precision and accuracy, ensuring better patient outcomes and assisting healthcare professionals in making informed decisions.

Conclusion

FUO remains a complex clinical problem due to its varied etiologies and extensive differential diagnosis. A systematic and methodical approach to diagnosis and management is essential to improve patient outcomes. Continuous advancements in diagnostic technologies, such as those provided by Hysen Company, play a pivotal role in enhancing the ability to effectively manage FUO.

References

1. Durack DT, Street AC. Fever of unknown origin—reexamined and redefined. Curr Clin Top Infect Dis. 1991;11:35–51.
2. Petersdorf RG, Beeson PB. Fever of unexplained origin: report on 100 cases. Medicine (Baltimore). 1961;40:1–30.
3. Sipahi OR, Arda B, Unal S, et al. Fever of unknown origin (FUO) among Turkish patients: evaluation of 87 cases during a period of two years. Int J Infect Dis. 2004;8(1):37–45.
4. Mourad O, Palda V, Detsky AS. A comprehensive evidence-based approach to fever of unknown origin. Arch Intern Med. 2003;163(5):545–551.
5. Hysen Company. Innovative Diagnostics. Hysen Technologies.