Bacterial Infections Flashcards
Superficial infection of skin caused by Staphlococcus auerus or Streptococcus pyogens
easily spread in unsanitary conditions
peak occurance during summer/early fall, moist climates
most common in school aged children
Clinical: facial perioral & perinasal, erythemia w/ superficial vesicles that quickly rupture and crust over, amber color, itching common, arise in areas of damaged skin
Diagnosis: presumptive based on clinical presentation, definitive diagnosis requires isolation of causative organisms in culture of skin
TX: topical or systemic antibiotic
Impetigo
What is a possible differential diagnosis for impetigo?
Herpes simplex
common over wide age range, calcified structures that develops in enlarged tonsillar crypts,
Clinical: enlarged crypts w/ yellowish debris (soft or calcified), variable size, foul smelling, solitary or multiple, radiographically present as radiopacities in midportion of ascending ramus.
Tx: none necessary unless associated w/ clinical symptoms (usu. fall out on own
Tonsillolithiasis
convoluted crypts of tonsils commonly filled w/ desquamated cells, foreign debris, and bacteria, soft deposits
tonsillar concretions
calcified deposits in tonsillar crypts
tonsilloliths
Chronic infection worldwide caused by Treponema pallidum (spirochete), spread by sexual contact, transplacental transmission, contaminated blood exposure, infection progresses through 3 stages, highly infectious in first 2 stages
Syphilis
Relatively painless ulceration (chancre), develops 3-90 days after exposure, most affect genital area, 4% are oral –> lip, buccal mucosa, tongue, resolves spontaneously in 3-8 weeks
ulcerations are non-specific and require biopsy for diagnosis
Good prognosis if identified early
Primary syphilis
develops 4-10 weeks after initial infection, generalized lymphadenopathy, erythematous maculopapular cutaneous eruption, mucous patches & condylomata lata of oral mucosa, split papules at angles of mouth, can often affect palm of hand and soles of feet
spontaneous resolution w/in 3-12 weeks but relapse may occur during the next year.
untreated pts enter latent period
Secondary syphilis
What could be a possible differential for lymphadenopathy?
brachial cleft cyst, TB
What could be a differential for a mucous patch related to syphilis?
pre-malignant lesion
can someone in the latent period of syphilis still transmit the disease to others?
yes
Develops after a latency period of 1-30 years, 30% of pts affected, may affect any tissue (vascular, CNS, skin, bones, soft tissues), gumma formation (necrotic lesions), oral involvement may produce palatal perforation
Tertiary Syphilis
What could be a differential diagnosis for palatal perforation from tertiary syphilis?
aggressive lymphoma, nasal inhalation of recreational drugs
Saddle nose deformity saber shins Hutchinson's Triad: * malformed incisors/mulberry molars * ocular interstitial keratitis (opacification of cornea) *VIII nerve deafness
Congenital Syphilis
Describe the histopathology of primary and secondary syphilis.
intense plasmacytic infiltrate
Describe the histopathology of tertiary syphilis.
characterized by granulomatous inflammation
What stain is used to identify spirochetes?
Warthin Starry stain
What is a negative aspect to syphilis screening tests?
they are very sensitive, but not specific to any one type of spirochete
When would you use dark-field microscopy?
When you have a non-oral syphilis lesion (b/c other spirochetes can be part of normal oral flora, does not work with oral lesions)
What is the treatment for syphilis?
PCN
pcn allergy: use doxycycline, tetracycline, erythromycin
caused by Mycobacterium tuberculosis, droplet transmission, endemicc in many areas of the world,
Clinical: on 5-10% infected pts progress to active, low grade fever, night sweats, fatigue, weight loss, chronic bloody cough, oral lesions rather uncommon, solitary chronic painless ulcer or granular lesion most common on gingiva or tongue, diagnose w/ PPD, chest radiograph, biopsy, culture (takes 4-6 wks), molecular testing
TX: combination of antibiotics
prognosis good in immunocompetent pt
emergence of resistant strains
tuberculosis
Describe the histopathology of TB.
usually necrotizing granulomatous inflammation (caseous necrosis), multinucleated giant cells, organisms stain using fast acid method (Ziehl-Neelsen stain)
caused by actinomyces species that normally inhabit mouth, often associated w/ local trauma, (55% in cervicofacial areas), may follow dental extraction or untx dental disease
Actinomycosis
