Pyrexia/Fever of Unknown Origin (PYO/FUO) Examination - Patient Management

Pyrexia/Fever of Unknown Origin (PYO/FUO)

·        Formal definition:  > 38 C, > 3 weeks, no known cause (ie normal admission tests already done).

·        However, often used to describe a temperature that that you haven‟t done any tests on yet

·        Usually an unusual presentation of a common disease

·        History, exam, investigations, time course, urgency and likely cause depend on setting:

o   Community acquired (Classic PUO)

o   Nosocomial PUO (ie hospital acquired)

o   Immune-deficit or HIV related PUO

·        Differential:

o   Neoplasm: lymphoma, leukaemia (check lymph nodes), other (hepatic, renal, other)

o   Infection:

§  Bacterial: Tb, abscess (subphrenic, hepatic, pelvic, renal – look for ­ neutrophils), endocarditis (any dental work?), pericarditis, osteomyelitis, cholangitis, pyelonephritis, PID, syphilis, cystitis

§  Viral: EBV, CMV, HBV, HCV, HIV, Varicella-Zoster

§  Parasitic: malaria, toxoplasmosis

§  Fungal

o   Connective Tissue: RA, SLE, Vasculitis (eg polyarteritis nordosa – check for Raynaud‟s phenomena – abnormal response in fingers to cold)

o   Miscellaneous: drug fever (especially penicillins, sulphonamides), Rheumatic fever, inflammatory bowel disease, granulomatous disease (eg Sarcoid), Fictitious/Munchausen‟s (eg injecting themselves with saliva)

·        Clues:

o   Weight loss Þ chronic

o   Check eyes: iritis in connective tissue disease, jaundice, etc

o   Check tonsils, glands, ears for infection

·        History:

o   Travel (eg malaria, did they have prophylaxis)

o   Exposure to others

o   Sexual history

o   Weight loss

o   Been to other doctors (had any antibiotics)

o   Occupational exposure (eg cows)

·        Exam:

o   Lymph nodes

o   Heart murmurs

o   Skin for rashes

o   Abdominal exam

·        Possible investigations:

o   Blood count

o   Blood cultures

o   Urine microscopy & culture

o   Liver function (eg hepatitis)

o   Viral serology

o   Malaria film

o   Chest X-ray

·       Pyrexia of unknown origin if returning from 3^rd world

·        Diagnose on blood film/culture:

o  Malaria

o  Dengue

o  Typhoid: usually constipated, used to die of peritonitis, bradycardia, high spiking fever, takes days for temperature to go down

·        Ross River

·        Syphilis

·        Filariasis (eg Samoa)

·        Other imported infections from Pacific:

o  Leprosy (mycobacterium leprae)

o  Yaws (Treponema pertenue)

o  Eosinophilic Meningitis

   Fever in a Neutropenic Patient

·        Eg in patients undergoing chemotherapy

·        Indicators of serious infection:

o  Signs and symptoms of infection will be reduced – can‟t mount an inflammatory response

o  Temperature:

§  > 38.5 C

§  > 38 for 4 hours

§  Patient fells unwell but no temperature

o  Neutropenia:

§  Neutrophils < 0.5 * 10E9/L (less than 0.2 Þ serious concern)

§  Neutrophils falling

§  Prolonged neutropenia (> 7 days)

·        Types of infection (drives focused history)

o  Respiratory: SOB, cough

o  Skin infection

o  Mouth and teeth

o  Perianal (pain on moving bowels and wiping)

o  Pain around central line

o  Less often: bowel & UTI

·        Focused exam:

o  Signs of septic shock: Pulse, BP and peripheral circulation

o  Chest: percussion and auscultation

o  Mouth: a good look around – abscesses will be sensitive to pain

o  Skin infections, especially lines

o  Quick abdominal

o  Exam perianal area – test for sensitivity to touch. Don‟t do PR (risk of minor trauma ® bacteraemia)

·        Investigations:

o  FBC

o  Blood culture (debate about whether to take it from the central line or not)

o  CXR

o  Swabs from anything that looks infected, including central line

o  Maybe CRP: ­ in bacteraemia

·        Normally don‟t find anything.  Over half infections are low grade line infections

·        If in doubt, treat empirically now.  If infected will deteriorate quickly:

o  Gentamycin + Ticarcillin (synthetic penicillin)

o  Monotherapy (eg imipenem)

o  +/- Vancomycin (for staph line sepsis)