Brainscape's Knowledge GenomeTM

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


See full index

Infectious Diseases > Pyrexia of Uknown Origin > Flashcards

Pyrexia of Uknown Origin Flashcards

1
Q

What is normal temperature?

A

36.0-37.7 degrees

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

Why is aural temperature slightly lower than oral and rectal temperature?

A

-Circadian variation lowest in morning
-Physiological variation
-Sweating due to endocrine causes (thyroid) or medications or feeling ‘hot’ not same as fever

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

What is Faget’s sign?

A

-Pulse rate rises approx. 10 bpm per degree
-Some infections associated with pulse fever dissociation
=Typhoid, brucellosis, Legionnaire’s disease

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

Pathogenesis of fever

A

-Trigger: pyrogen (PAMP, damage associated molecular patterns/ exogenous and endogenous)
-Pattern recognition of innate immune system (Toll)= signal transduction= cytokines
=IL1/6, hypothalamus generates cAMP
=Rest body temperature

-Sympathetic NS- noradrenaline release
-Thermogenesis in brown adipose tissues, vasoconstriction in periphery, metabolic rate raised through muscle contraction (shivering)

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

Causes of fever

A

-Infection
-Malignancy
-Tissue injury, thrombosis, infarction
-Inflammatory conditions (rheumatological)
-Medications

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

History approach to patient with undifferentiated fever

A

-Presenting symptom (fever features/ not just hot or cold)
-Associated symptoms (e.g., cough and sputum, organ system?)
-PMH (diabetes, immunosuppressants= susceptibility to infection?)
-Epidemiological risk factors for infections
-Symptoms to suggest focus of infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Epidemiological risk factors for infections

A

-Age, gender, occupation
-Travel history
-Sexual history
-Animal exposure, hobbies, dietary risk factors
-Recent antibiotic treatment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Symptoms that suggest a focus of infection (examination findings)

A

-Skin rash or infection, splinter haemorrhages
-Cough or chest pain/ crackles, pleural effusion, new murmurs (infective endocarditis)
-Urinary symptoms
=Dysuria, frequency, haematuria
-Headache, sore throat, myalgia
-Abdominal or loin tenderness, masses
-Neck stiffness, confusion
-Pus on tonsils, lymphadenopathy
-Diarrhoea
-Nonspecific sign like UTI

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

Non-specific tests to assess likelihood/ severity of infection

A

-Full blood count
=Neutrophilia
=Lymphopenia or lymphocytosis
=Raised platelet count
-ESR
-CRP

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

Supportive tests to facilitate management

A

-Urea (renal function, low BP)
-Electrolytes
-LFT (hepatic origin?)
-Calcium
-Albumin (negative base reactant, reduced in a cute response to fever so systemic response)

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

Specific tests to elucidate cause of fever

A

-Blood cultures: several sets
-Urine culture (usually mid-stream)
-Sputum culture
-Stool culture
-Throat swab for (viral) PCR
-Chest x-ray (exclude pneumonia)
-Brain imaging and lumbar puncture and CSF examination

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

Liver function test results

A

-Very high ALT? Viral hepatitis, CMV
-Raised alkaline phosphatase? =Obstructive/ Cholecystitis
-Moderate rise in ALT (most infections)
-Reduced albumin (a negative acute phase reactant) = a sign of severity and? chronicity

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

Syndromic approach to guide investigations

A

-Rash
-Lymphadenopathy
-Fever and jaundice
-Hospital associated fever
-Respiratory tract infections
-Cardiovascular
-Travel
-Drug fever

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

Rash causes

A
  • Childhood exanthems e.g. measles
  • Herpes viruses ; HSV, VZV, EBV, CMV
  • Enteroviruses
  • HIV
  • Neisseria meningitidis
  • Toxic shock syndrome
  • Syphilis
  • Rickettsial illnesses (travel)
  • Lyme disease
  • Still’s disease (rheumatological)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Lymphadenopathy causes

A

Streptococcal infection
* EBV, CMV, toxoplasma
* HIV
* Tuberculosis
* Syphilis
* Lymphoma
* Carcinoma
* Sarcoid

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

Fever and jaundice causes

A

Viral hepatitis
* Cholangitis
* Bacterial sepsis
* Hepatic abscess
* Leptospirosis
* Drug toxicity
* Auto-immune hepatitis
* Malignancy

17
Q

Hospital associated fever causes

A
  • Hospital associated
    pneumonia
  • Vascular catheter infection
  • Urinary tract infection
  • Surgical wound infection
  • Thromboembolism
  • Drug or transfusion
    reaction
18
Q

Respiratory tract infections cause

A
  • Viral upper respiratory tract infection
  • Streptococcal pharyngitis
  • EBV
  • Community-acquired pneumonia
  • Pleurisy and empyema
  • Tuberculosis
  • Pulmonary emboli
19
Q

Cardiovascular causes

A
  • Endocarditis
  • Pericarditis
  • Myocarditis
  • Atrial myxoma
  • Thrombo-embolic disease
20
Q

Travel causes

A
  • Malaria
  • Dengue
  • Typhoid
  • Dysentery
  • Thrombo-embolic disease
21
Q

Drug fever causes

A
  • Antimicrobials
  • Non-steroidals
  • Allopurinol
  • Phenytoin, carbimazepine and
    anti-seizure meds
  • Selective serotonin reuptake
    inhibitors
  • Chemotherapy e.g. bleomycin
22
Q

Fever with joint pain causes (arthralgia)

A

-Single joint
=Septic arthritis, secondary to bacteraemia
=Endocarditis with embolic phenomena
=Gonococcal infection
=Lyme disease
=Gout or pseudo-gut

-Osteomyelitis
-Discitis (back pain)

-Polyarticular
=Viral infections; exanthems (especially Parvovirus B19, Hep B)
=Rheumatological disorders (RA)

23
Q

Serology findings

A

-Useful and should be considered on all admissions with
fever; especially when high background incidence
=HIV, Hepatitis B and C

-Appropriate when multisystem symptoms, pharyngitis
or lymphadenopathy in young adults
=Epstein Barr IgM, CMV

-Reserved for particular epidemiological settings
=Coxiella burnetii, Brucella species, Leptospirosis species

24
Q

Investigation of persistent fever

A

-Revisit history
-Repeat initial investigations
=Blood and urine culture
-Imaging
=Chest X ray
=Abdominal imaging
=USS
=CT

25
Q

What is USS used for?

A

-Cheap and available
-Good for solid organs of upper abdomen
-Less good for bowel, retroperitoneum

26
Q

What is CT used for?

A

-Pelvic/ lower abdominal abscess (diverticular abscess)
-Retroperitoneal lymph nodes (malignancy, TB)

27
Q

Fever in immunocompromised hosts

A

-May have less obvious inflammation (masking signs like meningism, radiological appearances like infiltrates on CXR)
-Infectious syndromes
-Chemotherapy induced neutropenia
-Transplantation, HIV (not receiving antiretroviral therapy), high dose steroids, T-cell defects
-Hypogammaglobulinemia
-Asplenic (encapsulated bacteria)
-Anti-TNF therapy (mycobacterial disease)

28
Q

Causes of chemotherapy induced neutropenia

A

-Neutropenic fever
-Catheter-related infections fungal infections
-Underlying haematologic malignancy
-Side effects of chemotherapy

29
Q

Transplantation infections

A

-Pneumocystis pneumonia
-Cryptococcal infection
-Toxoplasma encephalitis
-Herpesvirus infections
-Mucosal candida infections
-Mycobacterial infections

30
Q

Causes of hypogammaglobulinemia

A

-Bacterial sino-pulmonary infection
-Giardiasis
-Chronic enteroviral infections
-Gastrointestinal tract
lymphoma
-Auto-immune phenomena

31
Q

Asplenic causes

A

Infections with encapsulated bacteria e.g. Pneumococcus, Haemophilus influenzae

32
Q

What is classified as fever of unexplained origin?

A

-Fever >38.3 degrees for >3 weeks
-Diagnosis uncertain after investigation for:
=3 out-patient visits
=3 days investigation in hospital
=One-week ambulatory investigation

33
Q

Usual cases of pyrexia of unknown origin

A

-Infection
-Neoplasm
-Connective tissue disorders
-Multisystem
-Miscellaneous
-Unknown

34
Q

Sub-groups to PUO

A

-Classical
-Nosocomial (hospital associated causes)
-Immunodeficient
-HIV

35
Q

Which tests were most useful in the investigation of PUO?

A

-Abdominal CT scan (“19%”)
=Intra-abdominal abscess
=Lymphoproliferative disorders
-Liver biopsy (“15%”)
-Temporal artery biopsy in the elderly (temporal arteritis)

36
Q

PUO changing practice

A

-Better molecular diagnostics
-PCR for 16S ribosomal RNA for detection and
identification of bacteria

-Better autoimmune serology
=Anti-CCP2 antibodies instead of rheumatoid factor

-Better radiology
=PET scanning

Infectious Diseases (25 decks)

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