Idiopathic Pyrexia

Question 1

Definition

Answer 1

Pyrexia or Fever is defined as a elevation above the normal body temperature (37°C) and it’s daily variation (0.8°C) so would be classed as a temperature over 38°C

Question 2

Epidemiology

Answer 2

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Question 3

Pathophysiology

Answer 3

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Question 4

Etiology/Risk Factors

Answer 4

Pyrogens all act on the hypothalamus causing it to reduce heat loss
Endogenous (cytokines)
Exogenous (Endotoxins from G-ve bacteria)
Tumours
Inflammatory

Question 5

Presentation

Answer 5

Idiopathic defined as no diagnosis after one of the following:
3 outpatient visits
3 days in hospital
One week of outpatient investigation

History:

• Travel
• Occupation
• Hobbies
• Family
• Past medical & history
• Drug
• Pattern of Fever

Examination

• Skin (rashes)
• Eyes (fundoscomy - TB)
• Oral (Ulcers - IBS)
• Nails (Splinter haemorrhage - endocarditis)
• Lymph nodes (Tumor or Infection)

Question 6

Lab Work Up

Answer 6

Urinalysis (Blood = Vasculitis)
Full Blood (WBC = lymphopenia) 
C-Reactive elevated 
Blood Cultures (infection)

Question 7

Imagining

Answer 7

Chest X-Ray (Tumour or TB)

Echocardiography (Endocarditis)

Question 8

Complications

Answer 8

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Question 9

Differential Diagnosis

Answer 9

.

Question 10

Treatment

Answer 10

Therapeutic trials of Steroid treatment

- Have to be confident there is no condition which may be exacerbated by them

Question 11

Prognosis

Answer 11

.

Question 12

Histology

Answer 12

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Question 13

Types

Answer 13

Nosocomial PUO:
- Develops in a hospital & undiagnosed after 3 days

Neutropenic PUO:
- Undiagnosed fever with neutrophils <500/mm3

HIV-Associated PUO:
- Fever in a patient with HIV and undiagnosed after 3 days as an inpatient or 4 weeks as an out patient