bacterial infections Flashcards
superficial infection of the skin caused by strep pyogens and/or staph aureus in unsanitary conditions
impetigo
during what time is impetigo most common?
summer or early fall in hot moist climates
in what age is impetigo most common
school aged children
superficial vesicles that quickly rupture and become covered in a thick, amber crust, pruitus common
impetigo
facial lesions around the nose and the mouth. many cases arise in areas of damaged skin; prexisting dermatitis, cuts, scratches, insects
impetigo
what does the definitive dx of impetigo require?
isolation of causative organisms in culture of skin
what is the tx of impetigo?
topical or systemic antibiotic
convoluted crypts of the tonsils that are commonly filled with desquamated cells, foreign debris, and bacteria (tonsillar concretions)
tonsillolithiasis
what is it called when tonsillolithiasis aggregate and undergo calcification?
tonsilloths
what do tonsillolithiasis appear as radiogreaphically
may present as radiopacities overlying the midportion of ascending ramus
what is the tx for tonsillolithiasis?
none unless associated with clinical symptoms
chronic infection found worldwide caused by the spirochete treponema pallidum
syphillis
what three things causes syphillis
- intimate sexual contact
- transplacental transmission
- contaminated blood exposure
during which three stages of syphilis are the most highly contagious?
first two
which stage of syphilis causes painless ulceration “chancre”
primary syphilis
when does primary syphilis occur?
3-90 days after exposure
what area is most affected by primary syphilis?
genital (2% oral)
when does secondary syphilis occur?
4-10 weeks after initial infection
erythematous maculopapular cutaneous eruption with generalized lymphadenopathy
secondary syphilis
what is the tx of secondary syphilis?
resolves spontaneously in 8-12 weeks, but may recur
*untreated pts then enter a latent period
when does tertiary syphilis occur?
after a latency period of 1-30 years
what tissues doe tertiary syphilis affect?
ANY TISSUE, CNS, vascular
what are some general findings of congenital syphilis?
- saddle nose deformity
- saber shins
- hutchinson’s triad (malformed incisors, mulberry molars, ocular interstitial keratitis
- eighth nerve deafness
which stages of syphilis show intense plasmactic infiltrate
primary and secondary
what is tertiary (gumma) syphilis characterized by?
granulomatous inflammation
how can the spirochetes of syphilis identified?
warthin-Starry stain
what are the screening tests of syphilis?
- VDRL
- RPR
what is the specific antibody test of syphilis
FTA
what test can be done for non-oral lesions of syphilis?
dark-field microscopy
what is the best way to tx syphilis
- penicillin is drug of choice
- if allergic, use tetracycline or erythromycin
*good prognosis if identified early and tx properly
endemic in many areas of the world and is estimated that 9 million ppl around the world develop the disease each year (2 million die)
tuberculosis
how is TB spread?
droplet transmission
where is TB most often found?
resurgence in inner cities of the US in the 1980s dur to HIV patients and immigrants from endemic regions
how many TB pts progress to active disease within 2 years after exposure?
5 percent
what are the clinical features of TB?
- low grade fever, night sweats, fatigue
- weight loss (consumption)
- chronic bloody cough
are oral lesions from syphilis common?
no, but if they are they will most likely be on the the gingiva and the tongue
solitary chronic painless ulcer or granular lesions
TB oral lesions
how do you dx TB?
positive skin test (PPD)
*only indicates exposure
- chest radiograph
- culture
- ID of organisms of biopsy material
- molecular testing (PCR)
TB has what type of cells?
multinucleated giant cells
how do you treat TB?
usually combo of antibiotics
- isoniazid, rifampin, and pyrainamide daily for 2 months)
- then ING and rifampin for 4 months
- ehtambutol or streptomycin also used
*anti-TB therapy works relatively rapidly resulting in a non-infectious state in two weeks
what is the prognosis for TB pts in an immunocompromised pt
generally good
what lowers the prognosis for TB?
when pts fail to take prescribed meds
-emergence of resistant strains
often associated with local trauma that is caused by any of several Actinomyces species that normally inhabit the mouth
actinomycosis
what parts of the body are affected my actinomysis?
- abdominal (25 percent)
- pulmonary (15 percent)
- cervicofacial (55 percent)
may follow dental extractions or untreated dental disease that is associted eith diffuse swelling and erythema and draining sinus tracts. Is associated with SULFUR GRANULES
cervicofacial actinomycosis
filamentous bacteria that form colonies surrounded by neutrophils. adjacent tissues may show granulomatous inflammation or granulation tissue
actino
what is the tx for actino
- removal of offending tooth
- high-dose antibiotics (usually penicillin)
- good prognosis with appropriate tx
what type of actinomycosis ussually responds to less aggressive treatment?
periapical actinomycosis
