Pyrexia of Unknown Origin

Question 1

Definition of PUO

Answer 1

> 38.3C fever on several occasions persisting greater than 3 weeks without diagnosis
Despite 1 week intensive investigations

Question 2

> 3/7 in hospital or >3 O/P visits with ambulatory Ix

Answer 2

Classical PUO

Question 3

Causes of Classical PUOs

Answer 3

Infections
Neoplasms
Connective tissue diseases
Misc. conditions (abscesses, endocarditis, tuberculosis, complicated UTIs)
Undiagnosed conditions

Question 4

Develops in patient following >24 hours in hospital

Answer 4

Healthcare associated PUO

Question 5

Causes of Healthcare associated PUO

Answer 5

Surgery
Drugs eg. vancomycin, penicillins, sertonergics
Medical devices (catheter, IV line bacteraemia)
LRTI (incl. ventilator associated in ITU)
C diff colitis
Immobilisaton

Question 6

Fever concomitant with neutropenia (

Answer 6

Neutropenic PUO - Medical Emergency
Chemotheraopy
Haem malignancies
Look for conditions that require neutrophils:
Aspergillus, bacterial sepsis, mycobacteria
GVHD
Drug Fever

Question 7

HIV +ve patients

Answer 7

HIV associated PUO

Question 8

Causes of HIV PUOs

Answer 8

Seroconversion
TB
Kaposi's Sarcoma
Bacterial
Disseminated MAI
PCP
CMV
Cryptococcus
Toxoplasmosis
Lymphoma Histoplasmosis
Drug Fever

Question 9

PUO diagnosis

Answer 9

Observe fever
Withhold therapy until diagnosis is reached if possible
Febrile neutropenia - empirical treatment started after taking samples for culture unless patient unstable
Vasculitis Screen - pANCA, cANCA Rho, La
Bence Jones protein electrophoresis
Dip urine/casts
Familial diseases eg FMF, Fabry’s disease, cyclic neutropenia
Returning traveller