Fever Of Unknown Origin

Question 1

What are the different aetiologies of PUO?

Answer 1

• Infection (25%)
• Malignancy
• Inflammation
• Other
• Undiagnosed (30%)

Question 2

What are the most common causes of PUO in children?

Answer 2

• about 45 % infective
• 45 % of undetermined aetiology

Question 3

What are the most common infective cuases of PUO?

Answer 3

• Tuberculosis
• Brucellosis
• Q fever
• Subacute bacterial endocarditis
• Complicated UTI
• Abscess

Question 4

What is the timeline for IgM immune response?

Answer 4

Generally 3 weeks
1. increase 1-2 weeks
2. Stay high 2-4 weeks
3. decrease

Question 5

What is the time for immune response for IgG antibodies?

Answer 5

Increase within 3-4 weeks

Question 6

What is sepsis?

Answer 6

Disorganised Host response to Infection

Question 7

What is septic shock?

Answer 7

Sepsis unresponsive to treatment and with end-organ failure

Question 8

What is healthcare-associated PUO?

What are some of the differentials?

Answer 8

• develops in a patient following > 24h of admission
• Hospital-acquired infections (LRTI, C. diff, UTI)
• Medical devices (catheter, IV line bacteraemia)
• Surgery
• Drugs (vancomycin, penicillins, serotonergics)
• Immobilisation

Question 9

What is neutropenic PUO?

Answer 9

Fever concomitant with neutropenia (500/uL) and subsequent lack of cellular response.

MEDICAL EMERGENCY

Question 10

What are some of the differentials for neutropenic PUO?

Answer 10

• Chemotherapy
• Haematological malignancies
• Drugs (clozapine, carbimazole)

Question 11

What are some causes of PUO in HIV+ve patients?

Answer 11

HIV +ve patients might regularly present with PUO

• Seroconversion
• Infection (TB, bacteria, PCP, MCV, etc.)
• Malignancy (Kaposi’s sarcoma, lymphoma)
• Drugs

Question 12

Other than a thourough screen for infections, what other investigations/ differentials could be done in asessment of PUO?

Answer 12

• Vasculitis screen: pANCA, cANCA, Rho, La etc… (Rheumatology r/v if arthritis)
• Bence Jones/protein electrophoresis (myeloma etc.)
• Dip urine/casts
• Familial diseases eg: FMF, Fabry’s disease, cyclic neutropenia
• Fever in returning traveler

Question 13

What is the definition of PUO?

Answer 13

• Temperature >38.3°C
• For >3 Weeks without diagnosis despite
• Extensive investigations (3 days in hospital, 1 week ambulantory)