GRANULOMATOUS DISEASES OF THE SKIN Flashcards
diseases or inflammatory reactions that are characterized by the formation of a granuloma are called what?
Granulomatous diseases
What is a Granuloma?
a focus of chronic inflammation made of microscopic aggregrates of macrophages that are transformed into epitheloid-like cells and are surrounded by a collar of mononuclear leucocytes principally lymphocytes and occasionally plasma cells with or without the presence of giant cells.
Mention 5 examples of infectious Granulomas?
Tuberculosis Leprosy Histoplasmosis Cryptococcosis Coccidioidomycosis Blastomycosis Cat Scratch disease
Itemize 5 examples of non-infectious granulomas
Sarcoidosis Crohn’s disease Berylliosis Wegener’s granulomatosis Churg-Strauss Syndrome Pulmonary Rheumatoid Nodules
What etiological agents of TB constitute the mycobacterium TB complex?
M. tuberculosis M. bovis(unpasteurized milk) M. africanum(africa) M. canetti(rare) M. microti(immunocompromised)
Mention 5 distinctive features of Mycobacterium TB?
obligate aerobe Slender, slightly curved & rod shaped AFB by Ziehl-Neelsen staining technique Lipids = 50% of dry weight divides every 16 to 20 hours can withstand weak disinfectants and can survive in a dry state for weeks.
Mycobacterium tuberculosis is an obligate anerobe (T/F)?
False
It’s an obligate aerobe
Mention 6 facts that depicts the Global burden of TB ?
~ 8 million new cases of active TB per year
2-3 million deaths worldwide per year
1 in 3 persons with Mycobacterium tuberculosis infection
new infections occur at a rate of one per second
one in ten latent infections will progress to active TB disease,
14.6 million chronic active TB cases
Mention 10 epidemiological indicators of risk for TB?
HIV positive , substance abuse diabetes mellitus , Silicosis prolonged corticosteroid/ immunosuppressive therapy cancer of the head and neck leukemia and Hodgkin’s end stage renal disease intestinal bypass or gastrectomy, chronic malabsorbtion syndromes low body weight Contact with infectious patient Healthcare worker Homeless or unstably housed Foreign-born from high prevalence country Residence in institution
How is TB transmitted?
Via coughing, sneezing, or spitting
A single sneeze can release up to 40,000 droplets.
Primary TB is seen in Non- immune host and often seen in children (T/F)?
True
Where is the usual location of the ghon focus ?
It is usually subpleural, often in the mid to upper zones
What constitutes the ghon Complex?
Ghon focus
Enlarged lymphatics
Enlarged regional LN
How long does it take for viable tubercle bacilli to be transported through the lymphatics to establish secondary sites?
within 2wks
development of cellular immunity (delayed-type hypersensitivity) in TB occurs when?
during the next 4 weeks(3–8 weeks)
positive reaction in the skin to an intradermal injection of protein from tubercle bacilli (tuberculin/PPD) occurs due to what?
development of cellular immunity (delayed-type hypersensitivity)
In active TB, 75% are asymptomatic (T/F)?
False
Show pulmonary symptoms
Mention 5 symptoms of tuberculosis?
Asymptomatic Chronic Cough(>3wks) Weight loss Night sweats Chest pain Fever
Extrapulmonary TB account for 25% of active cases (T/F)?
False
75%
Outline 5 extrapulmonary sites of TB affectation?
Pleura (tuberculous pleurisy) CNS(meningitis) Lymphatic system (scrofula of the neck) Urogenital TB Bone & joints (Pott’s dx of the spine) Skin TB
The incidence of cutaneous tuberculosis appears very high (T/B)?
False
It’s very low
Cutaneous tuberculosis shows varied immunological reaction of the skin to mycobacterium tuberculosis (T/F)?
True
Cutaneous involvement is a rare manifestation of tuberculosis (T/F)?
True
Classify cutaneous tuberculosis?
INOCULATION TUBERCULOSIS(EXOGENOUS SOURCES)
- Tuberculosis chancre
- Warty tuberculosis(verruca cutis)
- Lupus vulgaris (some)
SECONDARY TUBERCULOSIS(ENDOGENOUS SOURCES)
Contiguous spread —- scrofuloderma
Auto -innoculation —- orificial tuberculosis
HEMATOGENOUS TUBERCULOSIS
Acute miliary tuberculosis
Lupus vulgaris (some)
Tuberculous gumma
ERUPTIVE TUBERCULOSIS (TUBERCULIDS)
Micropapular —- lichen scrofulosorum
Papular. —-papular or papulonecrotic tuberculids
Nodular —- Erythema induratum