05 Bacterial infections Flashcards
impetigo
superficial skin infection, contact sports, scratching.
strep pyogenes (non-bullous), staph aureus (bullous).
vesicles rupture and cover with brownish crust.
treatment: non-bulous - mupirocin, bullous - antibiotics.
tonsillar plug
treponema pallidum
causes syphilis, treated with antibiotics.
highly infectious during first 2 stages, pregnancy transmission.
primary syphilis
chancre at initial exposure site - firm painless skin ulceration, 4-6week duration, regional lymphadenopathy.
secondary syphilis
1-6 months post primary, flu-like.
symmetrical reddish, non-itchy skin rash.
mucous patches - genitals/mouth.
condyloma lata (flat, whitish rash in moist areas).
optic neuritis and interstitial keratitis
latent syphilis
serologic proof without signs/symptoms.
early more contagious - treat with single, long acting penicillin.
late less contagious - treat with three weekly injections
tertiary syphilis
1-10yrs post infection.
cardiovascular, central nervous system trouble.
gumma - soft tumor-like granulomas of skin or mucous membranes anywhere on body.
leutic glossitis
neurologic syphilis
insanity (general paresis) during late stage.
personality/emotional changes, thin/irregular pupils.
tabes dorsalis - spinal cord disorder leads to shuffling gait.
syphilitic aortitis, aortic aneurysm, aortic regurgitation.
neurosyphilis higher w/HIV, lumbar puncture recommended.
congenital syphilis
mother with primary/secondary syphilis.
usually results in miscarriage, premature birth, stillbirths.
signs: frontal bossing, short maxilla, high arched palate, saddle nose, rhagades.
most symptoms develop after birth and are infectious.
rash, fever, swollen liver/spleen, anemia, jaundice.
newborns may develop poor feeding and rhinorrhea.
hutchinson’s triad: hutchinson’s teeth, interstitial keratitis, 8th nerve deafness
syphilis tests
wasserman test
darkfield illumination microscopy of fluid
rapid plasma reagin (RPR), venereal disease research laboratory (VDRL) - cheap, not specific.
most specific tests use monoclonal antibodies and IF: treponema pallidum hemagglutination test (TPHA), fluorescent treponemal antibody absorption (FTA-ABS)
gonorrhea
neisseria gonorrhea, gram negative diplococci.
sexual contact, cannot penetrate intact epithelium.
pelvic inflammatory disease (PID).
associated with chlamydia, cotreat all cases for both with ceftriaxone and doxycycline.
gonococcal ophthalmia neonatum (baby eye infection).
gonococcal pharyngitis
tuberculosis
mycobacterium tuberculosis.
infection must be distinguished from active disease.
attacks lungs, CNS, lymph, circulatory system, bones, joints, skin, etc.
50% lethal if untreated.
aerosol spread from active infection, not latent.
dangerous for immunocompromised and health care workers of high risk patients.
TB & HIV
HIV w/PPD+, uninfected - 1:10 chance developing active TB, highest in first 2 years and later in life.
HIV w/PPD+, infected - 1:8 chance developing active TB each year.
TB treatment
isolation until 3 AFB- sputum
direct observed therapy, multiple drugs.
prophylaxis: INH, rifampin, pyrazinamide
BCG vaccine effective for infants
TB types
consumption - bloody cough, pallor, wasting
lupus vulgaris - TB of skin
scrofula - swollen lymphatics
miliary - disseminated TB, invaded circulatory system, millet seed appearance on x-rays
extrapulmonary TB is not contagious
noma - cancrum oris, gangrenous stomatitis, necrotizing stomatitis.
tissue destruction of face.
associtated malnutrition, dehydration, poor hygiene, recent illness, malignancy, and weak immune system.
not communicable, cause unknown, poor sanitation risk factor.
high morbidity and mortality (80%), plastic surgery needed.
actinomycosis - actinomyces israelii, gram+ anaerobic bacteria.
acute, deep, suppurative abscess with draining sinus tracts, sulfur granules.
high daily dose of antibiotics, surgical drainage and debridement.
cat scratch disease - begins in skin, spreads to lymph nodes.
intracellular bacterium bartonella henselae, gram- rod.
kittens and ticks, symptoms similar to lyme disease, fatigue, headaches, fever, chills, malaise, tender lymphadenopathy, convulsions.
80% under 21.
self limitiing with or withou treatment.
local heat, analgesics, aspiration of node.
bacillary angiomatosis responds to erythromycin.
sinusitis
bilateral maxillary, frontal, spenoid sinuses, drain through ostia. all drain through middle meatus.
begins as a blockage of the osteomeatal complex that disrupts normal drainage, decreases ventilation and precipitates disease.
worse when bent over/supine (maxillary sinusitis worse when upright, relief when supine)
acute sinusitis
- precipitated by URTI
- virally damaged surface mucosa colonized by bacteria (Haemophilus influenzae, Staph Aureus, Streptococcus pneumoniae and Moraxella catarrhalis)
- fungal invasion 2° to diabetes, AIDS/transplant, antirejection drugs
- infection <4 weeks
chronic sinusitis
- allergies, environmental factors (dust/pollution), fungus, narrow air passage.
- congestion, headache, facial pain, malaise, thick green/yellow discharge, blurred vision
- infection >12 weeks
sinusitis treatment
-medication management (amoxicillin for acute), surgery, nasal endoscopy
