PUO Flashcards
What does PUO stand for?
Pyrexia of unknown origin
What is pyrexia?
Raised body temperature/fever
What is the definition of PUO?
Pyrexia/body temp >38 degrees, that cause is unknown/undiagnosed for 3 outpatient vists, 3 days in hospital or 1 week of outpatient investigations.
What are the different classes of PUO?
Classic
Nosocomial- develops in hospital, undiagnosed after 3 days
Neutropenic- undiagnosed fever in patients with neutrophils <500/mm cubed (most commonly seen in haematology patients)
HIV-associated- fever in a patient with HIV infection- present and undiagnosed for more than 3 days in inpatient or 4 weeks in outpatient.
Define Noscomical PUO
Develops whilst in hospital, undiagnosed for more 3 days
Define Neutropenic PUO
Pyrexia of unknown origin in a patient with <500/mm cubed neutrophils
Define HIV associated PUO
PUO in HIV positive patient, undiagnosed for 3 days as inpatient or 4 weeks as an outpatient.
What proportion of PUO remain undiagnosed?
1/4
What are some potential causes of PUO?
Malignancy, vasculitis, infections, HIV infection, inflammatory conditions, Tropical infections (these can even present years after travelling to an infected area as they can sometimes remain dormant).
What are some initial investigations done for PUO?
FBC Differential WBC count Blood cultures ESR and C-reactive protein U+Es Chest x-ray Urine sample and analysis LFTs May also take biopsy
What is a fabricated fever?
The fever is real but is induced by the patient self injecting substances such as soap or fecal matter, the microbiology and lack of problem in the area it points to may be the best clue, the patients tend to continue to self-induce this fever even when very ill, the management/treatment is to get a psychiatric expert involved.
What is the treatment for PUO?
Fluids
Resucitation
What is therapeutic trail and when is it used?
It is rarely used/last resort.
If mycobacterial infection is suspected then give anti-tuberculous therapy. If it is Mtb the patient will respond within 2 weeks.
If vasculitis or connective tissue disorder is suspected, steroids are given. Should see a response within 48hrs.
