Pyrexia of Unknown Origin (PUO) Flashcards
Define PUO?
Multiple Febrile Episodes that defy diagnosis after either:
- 3 Outpatient visits
- 3 Days in hospital
- 1 wk outpatient investigation
What are the types of PUO?
- Classical
- Nosocomial
- Neutropenic
- HIV associated
What initial tests would you run to assess the cause of a fever?
History & Exam first
- CXR
- Urinalysis & Microscopy
- FBC
- CRP & ESR
- Blood Cultures
- U&E + Creatinine
- LFTs
What if the patient has tropical travel in the last 3 wks?
Do blood tests for malaria, dengue, HIV and others
What if the patient has a new murmur as well as the fever?
Do a transoesophageal echo for endocarditis
What if the patient has a headache?
Do a temporal artery biopsy for GCA?
What if the patient has haematuria?
Renal biopsy & Auto-antibodies for polyarteritis
US for renal cancer
What if there’s a TB contact in the patient’s history?
Sputum sample for culture & ZN stain
Bone marrow biopsy
Mantoux test
If you have no idea where its from what scan could you do?
A PET CT is non-invasive and will localize any infection or inflammation causing the PUO
If you still don’t know what the PUO is after all the tests what can you do?
Therapeutic Trial
1st) Anti-TB, they should respond within 2 wks
2) If that fails try a steroid for vasculitis or connective tissue disorders, they should improve dramatically within 48 hrs
How can a PUO case end if you don’t find a cause?
Some will spontaneously resolve
Some you can control the symptoms with NSAIDs or Steroids
Some require regular re-appraisal until something changes enabling diagnosis
What could cause PUO when there’s no cause for PUO?
Fabricated Fever! induced by the patient such as by self-injection (E.g. of faecal matter) or eating soap.
How do we detect a fabricated fever?
USually the microbiology gives it away
I.e. you see microorganisms in the blood that shouldnt be able to get there, almost as if someone injected them intentionally
What do you do for a fabricated fever?
Psych Referral
