Pyrexia of unknown origin (PUO)

Pyrexia of unknown origin (PUO) is a complex medical condition that puzzles patients, healthcare professionals, and doctors. This is a mysterious fever, characterized by persistent high body temperature without any clear cause. These challenges the diagnostic skills of medical professionals. The current article explores the causes, symptoms, and diagnosis of pyrexia of unknown origin.

What is Pyrexia of Unknown Origin (PUO)?

Pyrexia of unknown origin is a fever of about 101 Fahrenheit or 38.3 degrees Celsius or higher that lasts for three or more weeks, with no clear diagnosis in spite of extensive evaluation after one week. The condition puzzles healthcare professionals after a wide range of diagnoses of infections, autoimmune disorders, malignancies, and drug reactions. This challenge in identifying the cause of pyrexia of unknown origin lies in the fact that requires a comprehensive and systematic approach.

Symptoms of pyrexia of unknown origin (PUO):

1. Persistent fever: The main symptom of the pyrexia of unknown origin (PUO) is a fever. It is about 101 ⁰C or more. Variations occur in this hyperthermia but it is irregular and non-episodic.
2. Weakness and fatigue: Patients feel weakness and often experience profound fatigue. These changes lead to lethargy and alternation daily lives of patients.
3. Loss of appetite and weight: Due to hyperthermia and its associated physiological abnormalities patients lose their appetite and weight.
4. Body aches: Patients of the PUO feel body aches, like headaches, stomachaches, & arthralgia (joint pain).
5. Swollen lymph nodes: In some case of PUO, there is swellings in the patient’s lymph nodes. These occur mostly when the PUO is linked with infections or malignancies.
6. In some case of PUO frequent night sweats also occurred.  

Causes of Pyrexia of Unknown Origin (PUO):

The following reasons are more commonly occur in the pyrexia of unknown origin;

1. infectious causes of Pyrexia of Unknown Origin:

About an average of 23 % of causes of PUO are infections.

• Viral infections: Viral infections result in the PUO are cytomegalovirus, infectious mononucleosis, and HIV.
• Bacterial infections: The bacterial infections that cause PUO are tuberculosis, salmonellosis, urinary tract infections, osteomyelitis, abscess, sepsis, brucellosis, and endocarditis etc.
• Parasitic: Plasmodial malaria, amoebic liver abscess, and toxoplasmosis
• Rickettsia: The infections that result in PUO from the bite of ticks and mites are Q-fever, and Rocky Mountain spotted fever.

2. Neoplasm:

About average 17 % of causes of PUO are neoplasm disorders such as Hodgkin’s disease, lymphoma, leukemia, and neuroblastoma.

3. Connective tissue disorders:

About 13 % of causes of PUO are Rheumatoid arthritis, polyarteritis, systematic lupus erythematosus, etc.

4. Miscellaneous Causes:

About 26 % of the PUOs are due to mixed reasons such as drug fever, factitious fever, anhidrotic ectodermal dysplasia, sarcoidosis, and Ulcerative colitis.  

5. Undiagnosed Causes:

About 21% of the PUOs are due to undiagnosed causes.

Diagnosing pyrexia of unknown origin (PUO):

Diagnosis of a fever of unknown origin can be a time-consuming process due to its enigmatic nature. The following protocols are used in the diagnosis of PUO;

1. Complete Medical History: To find any clue about PUO, a physician should start taking a thorough medical history of the patient. The most important questions that should be clarified are about hyperthermic episodes, sweating, chills, vomiting, nausea, cough, immunization, infections, travel, or drug use.

2. Physical Examination: A detailed and comprehensive examination is needed to find any visible symptoms. The physical diagnosis includes sweating, temperature, dehydration, abscess, skin lesions, abdominal pain, petechial hemorrhage, palpate lymphatics, eye conjunctiva, and bone tenderness.

3. Laboratory Tests: This diagnosis includes, complete blood tests, CBC, blood culture, urine tests, Typhoid test, Blood smear test, plasmodial test, bone marrow test, radioactive scans, and biopsy.

4. Imaging Studies: These tests are very successful for the identification of PUO and these include, X-rays, CT scans, and MRIs.

5. Biopsies: In some cases, biopsies are required to test sample tissues in the diagnosis of PUO.

6. Specialized Tests: These tests include immunological, serological, and molecular diagnostics,

Consultancy:

In complex cases, there is a need for consultants to discuss the condition of the patient with them. These consultants include rheumatologists, urologists, oncologists, gastrologists, hepatologists, and others having specializations in different fields.

Treatment:  

There should be the following steps required to cope with such an embarrassing and confusing condition;

1. The patients should be hospitalized as soon as possible.

2. The patients’ physical conditions should be monitored to avoid any critical situation.

3. symptomatic treatments should be taken, such as antipyretic, antiemetic, analgesics, and IV fluids should be given to patients.

3. The patient’s food should be monitored and try to switch to juices and soft food.

4. if a bacterial infection is suspected then use antibiotics.

Conclusion:

Pyrexia of unknown origin (PUO) is a very challenging and time-consuming disorder. It confuses both patients and physicians also. PUO is diagnosed by a systematic protocol with a critical analytical approach that includes history-taking, physical examination, laboratory diagnosis, Imaging, and biopsies. During and after diagnosis a patient should be hospitalized in order to intensive care and proper medication.