Dr. Honey Savla presents information on pyrexia of unknown origin (PUO). PUO is defined as a fever over 38.3°C for at least 3 weeks without a confirmed diagnosis after initial investigations. An approach to a PUO patient involves 4 stages - thorough history and screening tests in stage 1, followed by focused tests and imaging in stage 2, invasive procedures in stage 3 if needed, and therapeutic trials in stage 4. Prognosis is generally better the longer a diagnosis remains elusive, but delay affects outcomes for certain conditions like tuberculosis if not identified promptly.
2. Pyrexia of Unknown Origin (PUO)
Definition:
by Petersdorf and Beeson in 1961
“Temperature higher than 38.3°C (101°F) on atleast two occasions ,
persisting without diagnosis for at least 3 weeks,
no known immunocompromised state,
Diagnosis that remains uncertain after a thorough history taking physical
examination and obligatory investigations.
11. Stage 2
• Review history & repeat physical examination
• Specific investigations
• Repeat sampling of blood & other body fluids.
• Skin tests
• Blood for antibodies – HIV antibodies, CMV
antibodies, EBV antibodies.
12. • Serological tests for toxoplasmosis, psittacosis and
rickettsial infections, syphillis.
• Serology for rheumatologic disorders like antinuclear
and antineutrophilic cytoplasmic antibodies,
rheumatoid factor
• Quatiferon TB Gold in tube and T spot TB – detects
ϒ interferon release.
13. Microscopy:
• Direct examination of blood smears: malaria,
trypanosomiasis ,babesia, leishmania, relapsing fever
rat bite fever, ehrlichiosis.
• Intra cellular organisms, bacteria, inclusion bodies,
protozoal amastigotes.
14. Imaging studies:
• GI contrast study
• High resolution spiral CT
• Arteriography
• Echocardiography
• Duplex imaging
16. Stage 3
• Biopsy of liver and bone marrow
• Lymph node biopsy
• Blind biopsy of 1 or both temporal artery in
patient > 50 yrs
• Exploratory laparotomy
17. MANAGEMENT
• Therapy withheld until cause is found
• Empirical corticosteroids or anti inflammatories in
temporal arteritis.
• Vital sign instability & neutropenia –
Fluoroquinolones + piperacillin,
vancomycin + ceftazidime/cefepime/
carbapenem with or without aminoglycoside,
18. Management of Nosocomial PUO:
• Change of IV lines, catheters
• Empirical treatment:
Vancomycin for MRSA
Broad spectrum Gram negative coverage
Piperacillin + tazobactum
Ticarcillin + clavulinic acid
Meropenem
20. Stage 4
Therapeutic trials:
• Empirical treatment with corticosteroids or NSAIDS
or antimicrobials
• Antimycobacterial agents in AIDS & neutropenic
• Blind therapy- delay in correct diagnosis
21. PROGNOSIS
• Poorest prognosis - elderly & malignant
• Delay in diagnosis affects prognosis of
intraabdominal infections, miliary tuberculosis,
disseminated fungal infections & recurrent
pulmonary emboli
• Undiagnosed PUO for prolonged duration – good
prognosis.