Bacterial Infections Flashcards
Impetigo
Superficial infection of the skin caused by _ or _
Contagious and easily spread in crowded or unsanitary living conditions Peak occurrence during summer or early fall in hot, moist climates
Staphylococcus aureus and/or Streptococcus pyogens
Most common in school-aged children
Facial lesions often around nose and mouth
Erythema with superficial VESICLES that quickly rupture and become covered in a thick, amber crust; pruritus common (sensation to itch)
Many cases arise in areas of damaged skin; prexisting dermatitis, cuts, scratches, insect bites, etc
impetigo
Presumptive diagnosis based on clinical presentation
Definitive diagnosis requires isolation of causative organisms in culture of skin
Treatment: Topical or systemic antibiotic
Common; develop over wide age range
Calcified structures that develops in enlarged tonsillar crypts
Convoluted crypts of the tonsils are commonly filled with desquamated cells, foreign debris, and bacteria = _
Tonsillolithiasis
Tonsillar Concretions
Occasionally these aggregates undergo calcification = Tonsilloliths
Enlarged crypts filled with yellowish debris; varies from soft to fully calcified
Variable size
Foul smelling
Solitary or multiple
Radiographically, may present as radiopacities overlying the midportion of ascending ramus
Tonsillolithiasis
Tonsillolithiasis tx?
No treatment necessary, unless associated with clinical symptoms
Chronic infection, found worldwide Caused by the spirochete Treponema pallidum Spread by: Intimate sexual contact Transplacental transmission Contaminated blood exposure
Syphilis
Syphilis
Progression of infection through 3 stages
Highly infectious during _ stage
first two stages
Relatively painless ulceration – “chancre”
Develops 3-90 days after exposure
Most affect genital region; ~4% are oral
Lip, buccal mucosa, tongue
Resolves spontaneously in 3-8 weeks
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
secondary syphilis
Spontaneous resolution within 3-12 weeks, but relapse may occur during the next year
Untreated patients then enter a latent period
Develops after a latency period of 1-30 years
Approximately 30% of patients affected
May affect any tissue; vascular, CNS, skin, bones, soft tissues
Gumma formation
Oral involvement may produce palatal perforation
tertiary syphilis
Saddle nose deformity
Saber shins
Hutchinson’s triad: Malformed incisors (“Hutchinson’s incisors”) and molars (“mulberry molars”) Ocular interstitial keratitis Eighth nerve deafness
Syphilis - Congenital
with congenital syphilis what is the Hutchinson’s Triad
Malformed incisors (“Hutchinson’s incisors”) and molars (“mulberry molars”)
Ocular interstitial keratitis
Eighth nerve deafness
Syphilis - Histopathology
Primary and secondary lesions show intense _
Tertiary (gumma) is characterized by granulomatous inflammation
Spirochetes can be identified using the _
primary and secondary - plasmacytic infiltrate
Warthin-Starry stain
Tx and Px of syphilis
Penicillin remains the drug of choice
Doxycycline, tetracycline or erythromycin for PCN-allergic patient
Good prognosis if identified early and treated properly
Tuberculosis
Caused by Mycobacterium tuberculosis
_ transmission
Endemic in many areas of the world
Estimated that 8 million people around the world develop the disease each year
2-3 million die of TB or its complications
Droplet transmission
Resurgence in inner cities of the U.S in the 1980’s due to HIV patients and immigrants from endemic regions In 2014, there were 9,421 cases of active TB reported in the US More than 11 million in US with latent disease
Only 5-10% of infected patients progress from infection to active disease (often associated with immunosuppression)
Low grade fever, night sweats, fatigue
Weight loss (“consumption”)
Chronic bloody cough (hemoptysis
TB
TB – Oral Lesions
Rather uncommon
Solitary chronic painless ulcer or granular lesion
Most common on gingiva and tongue
May be due to hematogenous or direct implantation of organisms
TB - Diagnosis
Positive skin test with PPD (only indicates _)
Chest radiograph
Identification of organisms in biopsy material or sputum
Culture (may take 4-6 weeks) Molecular testing (PCR, etc.)
only indicates exposure
Histopathology
Usually necrotizing granulomatous inflammation (“caseous necrosis”)
Multinucleated giant cells
Organisms stain using the acid fast method (Ziehl-Neelsen stain)
TB
TB tx?
Usually combination of antibiotics:
Isoniazid (INH), rifampin, pyrazinamide and ethambutol daily for 2 months
Then, INH and rifampin (daily, 2x or 3x weekly) for 4 mos.
TB dental considerations ?
TB – Prognosis = Generally good in immunocompetent patient
Problems arise when patients fail to take prescribed medications properly Emergence of resistant strains
Must distinguish active from inactive disease, based on history, symptoms, medical consultation, etc.
Anti-TB therapy works relatively rapidly, resulting in a non-infectious state within two weeks
Solitary chronic painless ulcer or granular lesion
Most common on gingiva and tongue
Actinomycosis
Caused by any of several Actinomyces species that normally inhabit the mouth
Often associated with _
Abdominal (25%), pulmonary (15%) or cervicofacial (55%) areas may be affected
local trauma
May follow dental extraction or untreated dental disease
Diffuse swelling and erythema
Draining sinus tracts
“Sulfur granules” – colonies of organisms in purulent exudate
Cervicofacial Actinomycosis
Histopathology
Filamentous bacteria that form colonies
Bacterial colonies surrounded by neutrophils
Adjacent tissue may show granulomatous inflammation or granulation tissue
Cervicofacial Actinomycosis
Cervicofacial Actinomycosis tx?
Sounds like fungal but its bacterial
Removal of offending tooth
High-dose antibiotics, usually IV PCN for 2 weeks, then oral PCN for 2 weeks
Periapical actinomycosis usually responds to less aggressive treatment
Good prognosis with appropriate therapy
