Pyrexia/ Fever of unknown origin

Question 1

How is PUO defined and what is neutropenic PUO

Answer 1

-Fever of 38.8 for at least 3 weeks with no identified cause after 3 days of hospital evaluation or 3 outpatient visits

• Neutropenic PUO - fever over 38.3 on several occasions with neutrophil count of below 500/mm3
• HIV associated PUO- fever over 38.3 and HIV positive

Don’t wait 3 weeks in immunocompromised patients

Question 2

What initial investigations would you do in PUO

Answer 2

• 3 sets of blood cultures
• FBC, ESR, CRP, U&E, LFTS, Bone profile
• HIV testing
• MSSU (urine) and sputum
• CXR

Other investigations
-Echo (murmur/ valve issue) -USS Abdominal -CT/MRI spine -Bone marrow -Biopsy any lesions found