Pyrexia of unknown origin

Question 1

what is the normal body temperature and how does it vary?

Answer 1

37C +/- 0.8C

lower in the morning and rises as day goes on

Question 2

what a re the features of inflammation?

Answer 2

pyrexia
hypertension
tachycardia

Question 3

what substances are responsible for fever?

Answer 3

pyrogens

endogenous - our body releases cytokines in response to foreign pathogens which can cause fever

exogenous - toxins released by foreign pathogens can cause fever

Question 4

what is the outcomes of PUO?

Answer 4

most spontaneously resolve - most younger patients

some patients with no diagnosis respond to NSAIDS or steroids

Question 5

what are the causes of PUO?

Answer 5

unknown 
inflammation 
infection (least common as infections are picked up)
malignancy 
other

Question 6

what are the 4 categories of PUO?

Answer 6

classical PUO
nosocomial PUO - acquired in hospital, undiagnosed by 3 days
neutropenic PUO - neutrophils < 500
HIV- associated PUO - > 3 days inpatient or > 4 weeks outpatient in a patient with HIV

Question 7

a patient has had a fever of unknown origin for 3 weeks now. You take a history and he mentions that he was in Africa 2 months ago.
what investigations should you carry out?

Answer 7

malaria blood film
borellia burgdorferi blood film
also test for dengue fever

Question 8

a patient has had a fever of unknown origin for 5 weeks now. you take a history and he mentions that he has been injecting heroin for the past 5 years.
what investigations should you carry out?

Answer 8

hep B and C serology

HIV antigen test

Question 9

a patient has had a fever of unknown origin for 3 weeks. you take a history and routine examinations. on the urinalysis it shows microscopic haematuria.
what further investigations should you carry out?

Answer 9

ANCA (vasculitis)

renal ultra sound (renal cell carcinoma)

Question 10

if after further investigations and you can still not find the diagnosis for the fever of unknown origin, the patient is unwell and requires medical assistance.
what will you do?

Answer 10

give a therapeutic trial of anti-TB medication and steroids

Question 11

with a therapeutic trial of anti-TB meds and steroids, a patient gets a lot better by the day after due to the steroids.
what does this lean you towards for the diagnosis ?

Answer 11

giant cell arthritis or stills disease

Question 12

with a therapeutic trial of anti-TB meds and steroids, a patient gets a lot better within the next 2 weeks.
what does this lean you towards for the diagnosis?

Answer 12

TB

Question 13

you are taking a history form a patient who has had a fever for 4 weeks now but there has been no diagnosis.
she mentions that the fever normally comes and goes every 3-4 days.
what does this pattern of fever indicate?

Answer 13

Tertian or Quartan malaria

Question 14

you are taking a history form a patient who has had a fever for 4 weeks now but there has been no diagnosis.
you ask about rashes and she says that there is a rash on her leg but it comes and goes.
what does this pattern of rash indicate?

Answer 14

chronic meningococcaemia
connective tissue disease
stills disease