Pyrexia of Unknown Origin

Question 1

define a pyogen

Answer 1

substances which cause fever

Question 2

name an endogenous pyogen

Answer 2

cytokines

Question 3

what do pyogens act on?

Answer 3

the hypothalamic thermoregulatory centre

Question 4

what can cause a PUO?

Answer 4

> collagen 12%
neoplasm 18%
infection 30%

Question 5

what can cause PUO in HIV?

Answer 5

> mycobacterium tuberculosis
mycobacterium avium
unknown

Question 6

define fever

Answer 6

elevation of body temp. 38C as part of the systemic inflammatory response
(variation of up to 0.8C daily)

Question 7

true or false

variation In fever temperature is normally high in the morning and low in the early evening

Answer 7

false

it is normally low in the morning and high in the early evening

Question 8

what is the modern definition of PUO?

Answer 8

no diagnosis with more than 2 outpatient visits or 3 days in hospital or 1 week outpatient investigation

Question 9

what is a neutropenic PUO?

Answer 9

undiagnosed fever in patients with neutrophils <500/mm3

Question 10

what is an HIV PUO?

Answer 10

fever in a patient with an HIV infection that has been present and undiagnosed >3 days inpatient or 4 weeks outpatient

Question 11

what is a nosocomial PUO?

Answer 11

a fever that develops in hospital and is undiagnosed after 3 days

Question 12

what is the petersdorf and beeson definition of a PUO?

Answer 12

> 38.3C that has been recorded at multiple occasions for at least 3 weeks or defied diagnosis after 1 week in hospital.

Question 13

what would you want to check in the history of a patient with a PUO?

Answer 13

> travel
pattern of fever
occupation
transient rash

Question 14

what initial investigations would you perform in PUO?

Answer 14

> blood cultures (taken at time of fever)
> erythrocyte sedimentation rate
> c reactive protein
> chest x ray
> urinalysis and microscopy
> FBC
> differential WCC

Question 15

what general investigations could you perform in a patient with PUO?

Answer 15

> urea
creatinine
electrolytes
LFTs

Question 16

what further investigations could you carry out if the patient had been travelling in the tropics?

Answer 16

> anaerobic serology

> blood films (repeated)

Question 17

when might you carry out a transoesophageal echocardiogram in PUO?

Answer 17

if there was a new murmur

Question 18

what investigations might you carry out if a patient with PUO also had headaches and jaw claudication?

Answer 18

temporal artery biopsy

Question 19

what investigations might you carry out if a patient with PUO also had microhaematuria?

Answer 19

> US
Autoantibodies
(maybe renal biopsy)

Question 20

what investigations would you carry out if the patient with PUO also had TB contact?

Answer 20

> sputum smear
bone marrow
mantoux

Question 21

what invasive investigation might you carry out in PUO?

Answer 21

diagnostic laparotomy (rare) obtaining tissue for microscopy and culture

Question 22

if a patient has a history of drug misuse what might you screen for?

Answer 22

blood bourne viruses

Question 23

when might you do a therapeutic trail?

Answer 23

suspected vasculitis
suspected tissue disorder
suspected mycobacterial infection

Question 24

is spontaneous resolution more likely in the young or the old?

Answer 24

in the young

Question 25

what is a fabricated fever?

Answer 25

when a fever is real but self induced (self injection of feaces is common

Question 26

what might be the strongest clue that a fever is fabricated?

Answer 26

odd microbiology