Pyrexia of Unknown Origin
If a patient presented with a PUO and a history of tropical travel, how would you investigate them/
Blood for malaria parasites and dengue fever HIV test Bone marrow biopsy for Leishmaniasis
Normal body temperature can vary by how much?
0.8 degrees
When is a tropical cause of PUO unlikely?
> 21 days after return
What diseases might cause a daily spikes fever?
Abscesses, TB, Schistosomiasis
What diseases might cause a remitting fever (diurnal variation, not dipping to normal)
Amoebiasis, malaria, salmonella, kawasaki disease, CMV, TB
If you suspect a mycobacterial infection, what treatment should be used?
Anti-TB medication
If a patient present with a PUO and microhaematuria, what investigations would you do? What conditions might you be thinking about>
Autoantibodies +/- renal biopsy (polyarteritis) Ultrasound (renal cancer)
How would you investigate suspected Leishmaniasis?
Bone marrow biopsy
What are the problems with using imaging in patients with PUO?
Can't always differentiate between infection and inflammation Anatomical changes may not develop in immunocomprimised hosts (e.g. neutropenic patients and abscesses)
What diseases might cause a saddle back fever?
Colorado tick fever, borrelia, leptospira, dengue, legionnaires
Give an example of an endogenous pyrogen
Cytokines
What is a nosocomial PUO?
Develops in hospital, undiagnosed after three days
When is body temperature higher?
Early evening
If a patient presented with a PUO and a new murmur, what investigation would you do?
Echocardiogram (transoesophageal echo may be needed)
What is a fever?
Elevation of body temperature above normal 37 degrees
Give an example of an exogenous pyrogen
Endotoxins from gram negative bacteria
What is an HIV associated PUO?
Fever in a patient with HIV present and undiagnosed for more than 3 days in inpatient or 4 weeks in outpatient care
What is a fabricated fever? How is it managed?
Fever is real but self induced, e.g. by self injection. Get help from a psychiatrist
When is body temperature lower?
First thing in the morning
How should you investigate a PUO?
History + Examination CXR Urinalysis and microscopy FBC and WCC CRP ESR Blood cultures U+Es, creatinine, LFTs
Name 5 things that can cause PUO
Infection: TB, HIV, endocarditis, abscesses, empyema, bacteria, rheumatic fever, SBE, toxoplasmosis, parasites, malaria, schistosomiasis, trypanosomiasis, fungi, typhus Malignancy: lymphoma, metastatic disease, renal carcinoma Inflammatory: temporal arteritis, inflammatory bowel disease, SLE, vasculitis, RA, kawasaki disease, polymyalgia rheumatica, Still's disease Other: drug fevers, venous thrombosis, PE, sarcoidosis, stroke, chron's, UC, familial mediterranean fever
What disease might cause twice daily spikes fever?
Leishmaniasis
What two invasive investigations are often used for blind investigation in PUO?
Liver and bone marrow biopsy
What things might cause an intermittent fever?
Malaria, septicaemia, UTI, pelvic inflammatory disease, IE/SBE, TB
What are the main causes of HIV associated PUO?
Mycobacterium tuberculosis Mycobacterium avium Unown or more than 1 causative disease
Patients with no diagnosis sometimes still respond to what treatments?
NSAIDs and steroids
What is the criteria for PUO?
No diagnosis of fever after either 3 outpatient visits or 3 days in hospital or one week of outpatient investigation
What disease might cause a longer periodicity fever?
Pel Ebstein from lymphoma
If a patient presented with PUO and drug misuse, what investigations would you do?
Screen for blood borne viruses
What should you examine in CE for PUO?
Skin, eyes, oral cavity, nails, lymph nodes
If a patient presented with PUO and TB contact, what investigations would you do?
Sputum smear Bone marrow biopsy Mantoux test
If there is a suspected connective tissue disease or vasculitis, what treatment should be used?
Steroids
What are pyrogens?
Substances that cause a fever
Fever is part of what response?
Systemic inflammatory response
If a patient presented with a PUO and headaches, what investigations would you do?
Temporal artery biopsy CT PET
What should you ask about in a history for PUO?
Travel, occupation, hobbies, family history, past medical and surgical history, drug history, pattern of fever
What is a neutropenic PUO?
Undiagnosed fever in patients with a neutrophil count of < 500/mm3
