pyrexia of unknown origin

Question 1

definition

Answer 1

temp >38.3 celcius, recorded on multiple occassions with no diagnosis
:3 out patients visits
3 days in hospital
one week of out patient investigation

Question 2

types

Answer 2

Classical
Nosocomial
-usually infective/ drug induced
Neutropenic- undiagnosed fever with neutrophils <500
HIV assoc.- fever in HIV patient. undiagnosed for more than 3 days inpatient orfour weeks outpatient

Question 3

causes of classical PUO

Answer 3

infection: TB HIV endocarditis, abdominal abscess
malignancy-lymphoma, metastatic disease
inflammatory
temporal arteritis, IBD, SLE Vasculitis
others
drug fevers,venous thrombosis,

Question 4

assessment

Answer 4

• History
o Travel
o Occupation & hobbies – exposure to allergens
o Family history and age of onset - familial fevers e.g. tumour necrosis factor receptor-associated periodic syndrome – TRAPS
o Past medical and surgical history
o Drug history
-examination, skin eyes oral cavity

Question 5

investigations

Answer 5

o Chest X-Ray
o Urinalysis and urine microscopy
o Full blood count and differential white cell count
o C-Reactive Protein (CRP) and Erythrocyte Sedimentation Rate (ESR)
o Blood cultures taken at times of fevers
o Urea, creatinine, electrolytes, liver function tests

Question 6

Further investigation

Answer 6

tropical travel: blood for malarial parasites, dengue
less likely if >21 days since return
bone marrow biopsy for leishmaniansis

New murmur
Echocardiography

headaches
-temporal artery biopsy or CTPET

micro haematurita
auto antibodies +/- renal biopsy (polyarteritis)
ultrasound

TB contact
sputum smear bone marrow, mantoux test

Drug misuse-screen for blood borne viruses

Question 7

treatment

Answer 7

therapeutic trial

• suspected mycobacterial infection (anti-tuberculous therapy)
• suspeted vasculitis or conn tissue dis (steroids)
• response of temporal arteritis to steroids is dramatic
• patients with no diagnosis sometimes respond to NSAIDS

Question 8

fabricated fever

Answer 8

self injection of faeces
o Microbiology may be strongest clue
♣ multiple different organisms on blood culture at different times, especially faecal organisms found
o Patient often continues despite being very sick
o Psychiatric expertise should be sought rather than direct confrontation