Lecture 5: Fever of Unknown Origin & TB Flashcards
What is the definition of fever
- in the AM
- in the PM
in combination w/ ________
Definition of Fever
> 37.2 in AM
37.7 in PM
in combination w/incr in hypothalmic set point
What is the nornmal range for body temp
normal body temp range = 35.6 - 38.2
Comparing Temps
- elderly: higher or lower than avg body temp
- rectal temps: higher or lower than oral and core temps
- What is the effect ovulation has on temp?
- lowest temp at what time? what time for highest?
- 2 things that cause incr in oral temp
Comparing Temps
- elderly = lower than avd body temp
- rectal temps = higher than oral or core
- ovulation incr temp
- lowest temp = 6am, highest = 4-6pm
- incr oral temp w/smoking + chewing
- exposure
- aging
- sepsis
- CHF
- drug OD
- Hypoglycemia
- Renal or Hepatic Failure
are all causes of what?
- exposure
- aging
- sepsis
- CHF
- drug OD
- Hypoglycemia
- Renal or Hepatic Failure
all causes of HYPOthermia
- hypothalmic lesion
- Thyrotoxicosis
- Anticholinergic blockade
- Exercise
are all causes of what?
- hypothalmic lesion
- Thyrotoxicosis
- Anticholinergic blockade
- Exercise
all causes of HYPERthermia
others (obvious): heat stroke, malig hyperthermia
What are 2 major benefits of fever
- decr viral replication to fight infxn
2. suppress microbial growth
- incr immunoglobulin synthesis
- activation of T cells
- incr cytokine production
- incr NK cell activity
- incr phagocytic activity
are examples of ______
- incr immunoglobulin synthesis
- activation of T cells
- incr cytokine production
- incr NK cell activity
- incr phagocytic activity
are examples of the benefits of fever
What is the definition of FUO (Fever of Unknown Origin)
- 4 components
MEMORIZE AND KNOW THIS!!
definition of FUO (Fever of Unknown Origin)
- Fever > 38.3C
- illness lasting 3 wks
- NOT immunocompromised
- failure to reach dx w/ labs, XR
What is the MC etiology of FUO
MC etiology of FUO = Infections
Etiology of FUO: Infections
- are most caused by microbes in the environment or by normal flora in our body
Etiology of FUO: Infections
-Infections mostly caused by normal flora in our body
Etiology of FUO
-what are the 4 other major classifications for the cause of FUPO>
Etiology of FUO
- Neoplasia
- Misc
- Connective Tissue D/o
- Undiagnosed
FUO workup
- what 3 tests are generalized/less invasive and a good place to start when working up FUO
FUO workup
- CBC w/diff
- CMP
- UA & culture
what is more common as the cause of FUO
- uncommon dzs -OR-
- uncommon manifestations of common dzs
Cause of FUO
- Uncommon manifestations of COMMON DZs MORE COMMON than uncommon dz
FUO
- once the site of infection determined what should be done next
FUO
- site of infection determined –> start empiric therapy
Etiology of FUO
-what is a common infectious cause of FUO
common infectious cause of FUO = TB!!!!
Tuberculosis
- what is the name of the species that causes this infection
- what is the hallmark of this dz
- how is this dz spread
Tuberculosis
- cause = mycobacterium tuberculosis
- hallmark = CASEATING granulomas
- spread is by respiratory droplets
TB
- what 2 groups = incr risk of exposure to TB
- what 2 groups = incr risk of TB infxn
- what types of pts = incr risk of active TB once infected
(gen and 1 spp example)
TB
- Incr risk of exposure to TB
- close contacts of pts w/active TB + healthcare workers - Incr risk of TB infxn
- immigrants from high prev area, homeless - Incr risk of active TB once infected
- immunodeficient pts –> HIV+
What cells in the body are responsible for the pathophysiology and granuloma formation seen in TB
alveolar macrophages
What are the 3 outcomes of a TB infection
Outcomes of TB infection
- Primary TB
- Latent/Chronic TB
- Reactivation/2ndary TB
3 Outcomes of TB infection
- what is the ONLY outcome where pts are NOT contagious
- which outcome is a/w apical cavitary lesions
- which outcome is characterized/controlled by granuloma formation and a (+) PPD
- which outcome is the result of the initial infection
3 Outcomes of TB infection
- ONLY outcome where pts are NOT contagious = LATENT/Chronic TB
- which outcome is a/w apical cavitary lesions
- Reactivation/2ndary TB - which outcome is characterized/controlled by granuloma formation and a (+) PPD
- Latent/Chronic TB - which outcome is the result of the initial infection
- Primary TB
3 Outcomes of TB infection: Reactivation/2ndary TB
- what causes the reactivation of Latent TB
3 Outcomes of TB infection: Reactivation/2ndary TB
- cause of reactivation of latent TB = waning of immune defense
why is the formation of caseating granulomas (central necrosis, acidic, Low O2) imp in TB
creates a hostile enviro for MTB
Pt presents w/ constitutional Sxs, chronic productive cough and pleuritic chest pain. On lung exam you note rales, consolidation and dullness in the middle R lobe.
Dx? (be specific)
Dx = Primary TB (middle/lower lobe consolidation)
Extrapulmonary TB
- name of d/o that affects the vertebra
- name of the term for affecting the LNs
Extrapulmonary TB
- name of d/o that affects the vertebra = Pott’s Dz
- name of the term for affecting the LNs = scrofula
If a pt has HIV and TB what do they have an incr risk of
HIV + TB = incr risk of reactivation TB
Name of the test to screen for TB
PPD
PPD: Screening for TB
- how long wait to see result?
- what is a positive result?
- what rxn size is considered (+) for HIV+, immunosuppressed, or close contact w/active TB pt
- what rxn size is considered (+) for pts w/no RFs for TB
PPD: Screening for TB
- wait 48-72hrs
- (+) result = transverse induration
- > 5 mm = (+) for HIV+, immunosuppressed, or close contact w/active TB pt
- > 15 mm = (+) for pts w/no RFs for TB
What are the names of the 3 diagnostic studies used in suspected cases of ACTIVE TB
3 diagnostic studies used in suspected cases of Active TB
- Acid fast smear (bacilli) + sputum culture x 3 days
- CXR (PA + Lateral)
- Interferon Gamma Release Assay (Quantiferon)
what is the gold std for dx TB
AFB (Acid Fast Bacilli) cultures
What is the main indication of CXR for TB
to r/o active TB
Patterns of TB seen on CXR
- what type of TB is a/w middle/lower lobe consolidation?
- what type of TB is a/w apical cavitary lesions?
- what type of TB is a/w diffuse, small nodular lesions?
Patterns of TB seen on CXR
- middle/lower lobe consolidation = Primary TB
- apical cavitary lesions = reactivation TB
- Diffuse, small nodular lesions = Miliary TB
What is seen on CXR that indicates primary TB has healed
Granuloma on CXR indicates primary TB has healed
Active TB Tx
- Names of drugs given?
- how long these 4 drugs given?
- how long is the TOTAL active TB tx?
- what 2 drugs given after the initial phase (continuation phase)
Active TB Tx
- Drugs = RIPE or RIPS
- Rifampin, INH (+ Vit B6), Pyrazinamide, Ethambutol (or Streptomycin) - given for 2 months
- total duration of active TB tx = 6 mos
- Continuation phase drugs = RI
- Rifampin + INH (+ Vit B6)
PPx of TB - when should ppx be started
PPx of TB
indicated when exposure to TB and (-) CXR
Latent TB and PPx TB Tx
- what 2 things given in both situations
- how does the length of Tx differ if pt is HIV+
- what is the minimum ppx duration needed
Latent TB and PPx TB Tx
- INH + Vit B6
- HIV+ –> longer tx
- need ppx for at least 2 wks
