Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Year 3 - Infection > Pyrexia of unknown origin > Flashcards

Pyrexia of unknown origin Flashcards

1
Q

What is fever?

A

Fever - Elevation of body temp >37oC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

When does pyrexia occur?

A
  • Part of the systemic inflammatory response (Endogenous pyrogens = Cytokines)
  • Exogenous pyrogens = Endotoxins from gram negative bacteria
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much does body temperature change throughout a day and due to what?

A

Variation of up to 0.8oC:

  • Lowest in the morning
  • Highest in the early evening
  • Caused by circadian rhythm
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a pyrogen?

A

A substance that acts at the hypothalamic thermoregulatory centre to cause reduced heat loss, leading to fever

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the sources of pyrogens?

A
  • Endogenous e.g. cytokines

- Exogenous e.g. Endotoxins from Gram-ve bacteria

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is Petersdorf and Beeson (1961) definition of pyrexia of Unknown Origin?

A
  • Temp > 38.3C
  • Recorded on multiple occasions
  • Present for at least three weeks
  • Defied diagnosis after one week of hospital evaluation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the modern definition of pyrexia of Unknown Origin?

A
  • 3 outpatient visits; or
  • 3 days in hospital; or
  • One week of outpatient investigation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Nosocomial pyrexia of unknown origin?

A

Develops in hospital, undiagnosed after 3 days

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Neutropenic pyrexia of unknown origin?

A

Undiagnosed fever in patient with neutrophils <500/mm3

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

HIV-associated pyrexia of unknown origin?

A

Fever in a patient with HIV infection - present and undiagnosed fro more than 3 days in an inpatient or 4 weeks in an outpatient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most common cause of pyrexia currently?

A

Unknown cause, 51%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the second most common cause of pyrexia currently?

A

1) Inflammatory cause, 22%; followed by,
2) infection, 16%; followed by
3) malignancy, 7%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the second most common cause of pyrexia in 1950s?

A

Infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is the most common causes of HIV-related pyrexia of unknown origin

A

1) Mycobacterium tuberculosis, 21%
2) More than one causative disease
3) Mycobacterium avium, 18%
4) Unknown, 16%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

How to assess someone with pyrexia of unknown origin?

A

1) History - Travel, occupation, hobbies, family history, past medical and surgical history, drug history, pattern of fever

2) Examination (Be thorough) - Skin, eyes, oral cavity, nails and lymph nodes
- Repeating examinations is often worthwhile

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Which simple investigations for someone with pyrexia of unknown origin?

A
  • Chest X-Ray
  • Urinalysis and urine microscopy
  • Full blood count and differential white cell count
  • C-Reactive Protein and Erythrocyte Sedimentation Rate
  • Blood cultures taken at times of fevers
  • Urea, creatinine, electrolytes, liver function tests
17
Q

Which investigation(s) for someone with pyrexia of unknown origin who has recently travelled to a tropical region?

A

Blood - Malarial parasites, dengue, HIV,

Bone marrow - Leishmaniasis

18
Q

Which investigation(s) for someone with pyrexia of unknown origin who has a new murmur?

A

Echocardiography

19
Q

Which investigation(s) for someone with pyrexia of unknown origin who is suffering headaches?

A

Temporal artery biopsy

20
Q

Which investigation(s) for someone with pyrexia of unknown origin who has micro haematuria?

A

Auto-antibodies +/- renal biopsy (polyarteritis)

Renal Ultrasound

21
Q

Which investigation(s) for someone with pyrexia of unknown origin who has had TB contact?

A

Sputum smear
Bone marrow
Mantoux

22
Q

Which investigation(s) for someone with pyrexia of unknown origin who has has drug misuse?

A

Screen for blood-borne viruses

23
Q

What is the issue with imagine in unknown pyrexia?

A

Cannot always differentiate between infection and inflammation

Anatomical changes may not develop n those who are immunocompromised

24
Q

What imaging techniques are used in pyrexia of unknown cause?

A

1) CT-PET (Positive emission tomography) Using FDG (Fluorodeoxyglusose marker)
2) CT
3) Ultrasound

25
Q

Which invasive investigations are used in pyrexia of unknown causes?

A
  • Obtain tissue cultures and histology
  • Bone marrow and liver often examined as part of blind investigation (Malignancy, TB, lymphoma)
  • Diagnostic laparotomy (Rarely)
26
Q

Which treatments are used in pyrexia of unknown causes?

A

1) Therapeutic trial:
- Rare
- Anti-tuberculosis therapy - response usually within two weeks if the cause
- Steroids for a vasculitis response usually within 48hrs if the cause

27
Q

What is a fabricated fever?

A

Fever is real but self induced:

  • Self injection is common
  • Microbiology is often strongest clue
  • Patient often continues even when very sick
28
Q

When there is fabricated fever what should be done?

A

Psychiatric consultation rather than direct confrontation

29
Q

Who is more likely for spontaneous resolution of pyrexia of unknown cause?

A

The young versus the elderly

Year 3 - Infection (16 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions