23 - 157 - TUBERCULOSIS AND INFECTIONS WITH ATYPICAL MYCCOBACTERIA Flashcards
2 most frequent forms of skin tuberculosis
- Lupus vulgaris
- Scrofuloderma
Common in the tropics
Srcofuloderma , verrucous
LV is more than twice as common in what gender
Women
tuberculosis verrucosa cutis is more often found in what gender
Male
miliary tuberculosis common in what age group
children, adults w/ AIDS/immunocompromised
Scrofuloderma usually occurs in what age groups
Adolescents and elderly
Occurs in all age groups
Lupus vulgaris
Cutaneous TB caused by exogenous infection
- Primary inoculation tuberculosis
- Tuberculosis verrucosa cutis
Cutaneous Tuberculosis caused by endogenous spread with high host immune status
Lupus vulgaris
Scrofuloderma
Mode of transmission-
Scrofuloderma -
Lupus vulgaris -
Acute miliary tuberculosis-
Scrofuloderma - Direct extension
Lupus vulgaris - Lymphatics, Hematogenous, Contiguous spread
Acute miliary tuberculosis- Hematogenous
most common cause of disseminated bacterial infections in patients with AIDS in the United States,
Mycobacterium avium-intracellulare complex
In AIDS patients, ___________ is more common than M. tuberculosis.
Mycobacterium kansasii
T/F. Populations that have been in longstanding contact with tuberculosis are, in general, less susceptible than those who have come into contact with mycobacteria more recently
TRUE
presumably reflecting widespread immunity from subclinical infection.
Local tuberculin reaction reaches maximum intensity after __ , consist of ___
48 hours
Sharply circumscibed area of erythema and induration
Tuberculin sensitivity usually develops how many weeks after infection?
2 to 10 weeks after infection and persists throughout life.
T/F
In patients with clinical tuberculosis, an increase in skin sensitivity usually indicates a worse prognosis, and in tuberculous skin disease accompanied by high levels of skin sensitivity, the number of bacteria within the lesions is large
FALSE
In patients with clinical tuberculosis, an increase in skin sensitivity usually indicates a FAVORABLE prognosis, and in tuberculous skin disease accompanied by high levels of skin sensitivity, the number of bacteria within the lesions is SMALL
Quantify tuberculin reaction, measure specific antgen-driven interferon y synthesis by whole blood cells approved by FDA in 2005
QuantiFERON-TB Gold (QFT-G)
Specimen for QuantiFERON-TB Gold (QFT-G)
Blood
Results based on anount of IFN-y released in response to antigens
QuantiFERON-TB Gold (QFT-G)
More sensitive than tuberculin skin test
QuantiFERON-TB Gold (QFT-G)
QuantiFERON-TB Gold (QFT-G) negative in ____
Indeterminate in ____
early tuberculosis
immunocompromised
measures the number of IFN-γ–producing T cells
T-SPOT.TB test
For QFT-G, the antigens include mixtures of synthetic peptides representing 2 M. tuberculosis proteins:
ESAT-6 and CFP-10
After incubation of the blood with antigens for 16 to 24 hours, the amount of interferon (IFN)-γ is measured.
If the patient is infected with M. tuberculosis, their white blood cells will release IFN-γ in response to contact with the TB antigens. The QFT-G results are based on the amount of IFN-γ that is released in response to the antigens.
indicated in diagnosing both TB disease and latent TB infection
QuantiFERON-TB Gold (QFT-G)
hallmark of tuberculosis and infections with some of the slow-growing atypical mycobacteria
tubercle: an accumulation of epithelioid histocytes with Langhans-type giant cells among them and a varying amount of caseation necrosis in the center, surrounded by a rim of lymphocytes and monocytes
tuberculosis verrucosa cutis and localized forms of LV without evidence of associated internal tuberculosis may be treated with ______________
Isoniazid alone for up to 12 monhs
Define Extensively multidrug-resistant TB
resistance to at least rifampicin and isoniazid from among the first-line anti-TB drugs (which is the definition of multidrug resistant TB) in addition to resistance to any fluoroquinolone, and to at least 1 of the 3 injectable second-line anti-TB drugs used in TB treatment (capreomycin, kanamycin, and amikacin).
Define multidrug-resistant TB
resistance to at least rifampicin and isoniazid from among the first-line anti-TB drugs
Incubation period of primary inoculation tuberculosis
2 - 4 weeks
Sites of predilection of PRIMARY INOCULATION TUBERCULOSIS (TUBERCULOUS CHANCRE, TUBERCULOUS PRIMARY COMPLEX)
face, including the conjunctivae and oral cavity, as well as the hands and lower extremities
Is the ulcer in inoculation tuberculosis painless or painful?
Painless
Slowly progressive, regional lymphadenopathy develops how many weeks after infection
3 - 8 weeks
Most prominent histopathologic features of TVC
pseudoepitheliomatous hyperplasia with marked hyperkeratosis, a dense inflammatory infiltrate, and abscesses in the superficial dermis or within the pseudoepitheliomatous rete pegs
T/F. Typical tubercles or tuberculoid granuloma are uncommon in TVC
TRUE
postprimary, paucibacillary form of tuberculosis caused by hematogenous, lymphatic, or contiguous spread from elsewhere in the body
LUPUS VULGARIS /TUBERCULOSIS LUPOSA
Most prominent histopathologic feature of lupus vulgaris
Formation of typical tubercles
Apple jelly nodules seen in diascopy are highly characteristic of which cutaneous TB?
Lupus vulgaris
subcutaneous tuberculosis leading to cold abscess formation and a secondary breakdown of the overlying skin
Scrofuloderma
represents contiguous involvement of the skin overlying another site of infection (eg, tuberculous lymphadenitis, tuberculosis of bones and joints, or tuberculous epididymitis)
Scrofuloderma
Most common locations of scrofuloderma
parotideal, submandibular, and supraclavicular regions
rare form of tuberculosis of the mucous membranes and orifices that is caused by autoinoculation of mycobacteria from progressive tuberculosis of internal organs
ORIFICIAL TUBERCULOSIS (TUBERCULOSIS ULCEROSA CUTIS ET MUCOSAE, ACUTE TUBERCULOUS ULCER)
Most frequently affected area in orificial tuberculosis
tongue is most frequently affected, particularly the tip and the lateral margins
What entities belong as tuberculids
Lichen scrofulosorum
Papulonecrotic tuberculid
Entities that are considered facultative tuberculids
Nodular vasculitis/ erythema induratum of Bazin
Erythema nodosum
uncommon lichenoid eruption ascribed to hematogenous spread of mycobacteria in an individual strongly sensitive to M. 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 histopath finding of papulonecrotic tuberculid is the involvement of _____________
Blood vessels
and consists of an obliterative and sometimes granulomatous vasculitis leading to thrombosis and complete occlusion of the vascular channels.
third most frequent mycobacterial pathogen
M. Ulcerans
The painless nature of the ulcer in M. Ulcerans/ Buruli ulcer disease has been attributed to nerve damage and tissue destruction caused by wha toxin?
Mycolactone toxin
Buruli ulcer is caused by what Mycobacterial species?
M. Ulcerans
atypical Mycobacterium most closely related to M. tuberculosis
M. Kansasii
