Chapter 157 - Tuberculosis and Infections With Atypical Mycobacterium Flashcards
Main cause of death of patients infected with HIV
Tb
TB is currently ranked ___ leading cause from an infectious agent,ranking higher than HIV/AIDS
9th
The highest burden of TB was in 5 countries
India Indonesia China Philippines Pakistan
In contrast to obligate pathogens, ___ do not cause disease by person to person spread
Facultative pathogens
2 most frequent forms of skin tuberculosis
Lupus vulgaris
Scrofuloderma
Most common cause of disseminated bacterial infection in patients with AIDS in the US
Mycobacterium kansasii
Incidence of TB in patients with AIDS is almost ____ than that in the general population
500 times
Local ID injection leads to delayed hypersensitivity reaction with macimum intensity by 48 hours
Tuberculin reaction aka Koch phenomenon
Tuberculin sensitivity is necessary for immunity.
True or False
False
For Quantiferon Tb GOLD test, (2) proteins are incubated for 16 to 24 hours and the amount of ___ produced by T cells are measured
ESAT-6 and CFP-10
IFN gamma
Histopath hallmark of TB
Tubercle - accumulation of epithelioid histiocytes with Langhans giant cells and caseation necrosis in the center
Only ___% of PCR positive patients respond to antiTB therapy
80%
TVC and localized forms of LV may be treated with ___
INH alone for up to 12 months
Extensively multidrug resistant TB is defined as
Resistance to at least Rifampicin + INH \+ Resistance to any fluoroquinolone \+ Resistance to second line anti Tb drugs (Capreomycin, Kanamycin, Amikacin)
First line drugs of AntiTb (4)
Rifampin/ Rifapentine/Rifabutin
Isoniazid
PZA
Ethambutol
Second line anti Tb drugs (9)
Amikacin/Kanamycin P-Aminosalicylic acid Capreomycin Cycloserine Ethionamide Gatifloxacin Levofloxacin Moxifloxacin Streptomycin
Introduced into tissue via minor wounds eg. Unpasteurized milk, tooth extraction, mucosal trauma.
Primary inoculation Tb/ Tb Chancre/ Tb Primary Complex
Ulcer with little or no tendency to heal with unilateral regional LN in a child arousing suspicion
Primary inoculation Tb/ Tb Chancre/ Tb Primary Complex
PPD of Primary inoculation Tb/ Tb Chancre/ Tb Primary Complex
‘-‘ —> ‘+’
Paucibacillary disorder caused by exogenous reinfection in previously sensitized individuals with high immunity
Tuberculosis verrucosa cutis aka Wart tuberculosis aka Prosecutor’s wart aka Lupus verrucosis
Histopath feature of tuberculosis verrucosa cutis
Pseudoepitheliomatous hyperplasia with marked hyperkeratosis, dense inflammatory infiltrate, and abscesses in the superficial dermis or within the pseudoepitheliomatous rete pegs
Typical tubercles are common in tuberculosis verrucosa cutis.
True or False
False, uncommon
Lupus vulgaris is an extremely chronic, progressive form of cutaneous Tb occurring in individuals with ___ immunity and a ___ degree of tuberculin sensitivity.
Moderate; high
On diascopy, LV shows
Apple jelly color
HPx feature of lupus vulgaris
Formation of typical tubercles.
Acid fast bacilli are not found
PPD result of LV
‘+’ —> ‘-‘ —> ‘+’
LV may lead to development of ff carcinoma
SCC > BCC
Pulmonary TB is ___ times more frequent in parients with LV than in the general population
4 to 10 times
Subcutaneous TB leading to cold abscess formation and secondary breakdown of overlying skin
Scrofuloderma/ Tuberculosis verrucosa cutis
Areas most commonly affected by scrofuloderma (3)
Parotideal
Submandibular
Supraclavicular
Frequently affected site of orificial tb
Tongue (tip and lateral margins)
Soft & hard palate
Lips
In normal course of BCG vaccine, an infiltrated papule develops after approximately ___ weeks, attains a size of 10 mm by ___ weeks
2; 6 to 12
Tuberculin sensitivity occurs ___ weeks after vaccination
5 to 6
Conditions in which Mycobacterium tuberculosis/ Mycobacterium bovis appears to play a significant role
Tuberculids
- Lichen scrofulosorum
- Papulonecrotic tuberculid
Conditions in which Mycobacterium tuberculosis/Mycobacterium bovis may be one of several pathogenic factors
Facultative tuberculids
- Nodular vasculitis/ erythema induratum of Bazin
- Erythema nodosum
No relationship to tuberculosis
Nontuberculids
- Lupus miliaris disseminatus faciei
- Rosacea-like tuberculid
- Lichenoid tuberculid
Uncommon lichenoid eruption ascribed to hematogenous spread of mycobacteria in an individual strongly sensitive to Mycobacterium tuberculosis
Lichen scrofulosorum
Symmetric eruption of necrotizing papules, appearing in crops and healing with scar formation that occurs preferentially in children or young adults
Papulonecrotic tuberculid
Cardinal feature of papulonecrotic tuberculid
Involvement of the blood vessels
Treatment for patients with extrapulmonary Tb
Initiation: RIP 5 days for 8 weeks
Continuation:
A- RI 5 days for 18 weeks
If PZA cannot be used, treatment for extrapulmonary TB consists of
Initial: RIE 5 days x 8 weeks
Continuation: RI 5 days x 31 weeks
Daily dosage for antiTb drugs
R 10 mkday (600mg)
I. 5mkday (300mg)
P. 25 mkday (2000mg)
E. 18 mkday (1600mg)
Patients who received 2 months of antiTb drugs but still has cavitation on CXR and positive cultures at completion should receive ___ month continuation phase
8 mos
DOT is given ___ times per week and is not recommended for HIV positive patients with CD4 count less than ___ ceels/ml
5
100
___ should not be given to HIV + patients
INH + Rifapentine
Tuberculin sensitivity develops ___ after infection and persists throughout life
2-10 weeks
PCR testing showed 100% sensitivity and specificity in multibavillary disease and 55% sensitivity in paucibacillary disease.
True or False
True
