Bacterial infections

Question 1

what is Impetigo?

Answer 1

Superficial infection of the skin caused by Streptococcus pyogens and/or Staphylococcus aureus

Question 2

how is impetigo spread? during what times is it most common?

Answer 2

Contagious and easily spread in crowded or unsanitary living conditions

Peak occurrence during summer or early fall in hot, moist climates

Question 3

Impetigo is Most common in what group?

Answer 3

school-aged children

Question 4

Clinical presentation of Impetigo:

Answer 4

Superficial vesicles that quickly rupture and become covered in a thick, amber crust; pruritus common

Facial lesions often around nose and mouth

Many cases arise in areas of damaged skin

Question 5

How is impetigo diagnosed?

Answer 5

Presumptive diagnosis based on clinical presentation

Definitive diagnosis requires isolation of causative organisms in culture of skin

Question 6

what is found in the tonsils of someone with Tonsillolithiasis?
(tonsil stones)

Answer 6

Convoluted crypts of the tonsils are commonly filled with:

• desquamated cells
• foreign debris
• bacteria

Question 7

what is the name for the mass of cells/debris found in patients with Tonsillolithiasis?

Answer 7

Tonsillar Concretions

Question 8

what are Tonsilloliths?

Answer 8

when tonsillar concretions CALCIFY

does not happen in all cases of tonsillolithiasis

Question 9

Clinical presentation of Tonsillolithiasis:

Answer 9

Enlarged crypts filled with yellowish debris; varies from soft to fully calcified

Variable size

Foul smelling

Solitary or multiple

Question 10

when taking radiographs of patients with Tonsilloliths, these stones may present as radiopacities overlying the midportion of the _____________

Answer 10

ascending ramus

Question 11

what organism causes syphilis?

Answer 11

Caused by the spirochete Treponema pallidum

Question 12

signs of primary syphilis:

Answer 12

Relatively painless ulceration – “chancre”

Develops 3-90 days after exposure

Most affect genital region;

Question 13

signs of secondary syphilis:

Answer 13

Develops 4-10 weeks after initial infection

Erythematous maculopapular cutaneous eruption

Painless generalized lymphadenopathy

Mucous patches & condylomata lata of oral mucosa

Split papules at angles of mouth

Question 14

after secondary syphilis symptoms resolve, the infection may enter a _______ period

Answer 14

latent period

Question 15

tertiary syphilis develops after how long?

Answer 15

Develops after a latency period of 1-30 years

Question 16

what symptoms of a tertiary syphilis infection can be seen by a dentist?

Answer 16

Gumma formation

Oral involvement may produce palatal perforation

Question 17

T/F: over half of patients with untreated secondary syphilis will develop tertiary syphilis

Answer 17

FALSE

only 30% progress to tertiary

Question 18

what diseases are caused by congenital syphilis?

Answer 18

Saddle nose deformity

Saber shins

Hutchinson’s triad

Question 19

what are the 3 characteristics of “Hutchinson’s triad”?

Answer 19

Malformed incisors (“Hutchinson’s incisors”) and molars (“mulberry molars”)

Ocular interstitial keratitis

Eighth nerve deafness

Question 20

what are the 3 ways syphilis can be diagnosed?

Answer 20

1) Screening tests, e.g., VDRL, RPR
2) Specific antibody tests, e.g., FTA
3) Dark-field microscopy for non-oral lesions

Question 21

Primary and secondary syphilis lesions show intense __________ infiltrate

Answer 21

plasmacytic

Question 22

Tertiary (gumma) syphilis is characterized by what type of inflammation?

Answer 22

granulomatous inflammation

Question 23

Spirochetes (like syphilis) can be identified using the ____________ stain

Answer 23

Warthin-Starry

Question 24

Worldwide, how many people become infected with TB each year?

Answer 24

9 million

2 million die per year

Question 25

how many people in the U.S. have a latent TB infection?

Answer 25

10-15 million

Question 26

Clinical features of TB:

Answer 26

Only 5% of infected patients progress to active disease within 2 years after exposure Low grade fever, night sweats, fatigue Weight loss (“consumption”) Chronic bloody cough LYMPH NODE SWELLING

Question 27

characteristics of Oral TB lesions:

Answer 27

Solitary chronic painless ulcer Most common on gingiva and tongue May be due to hematogenous or direct implantation of organisms

Question 28

How is TB diagnosed?

Answer 28

Positive skin test with PPD (only indicates exposure) Chest radiograph Culture (may take 4-6 weeks) Identification of organisms in biopsy material or sputum Molecular testing (PCR, etc.)

Question 29

what type of inflammation is characteristic of a Tuberculosis infection? what cell type is predominant in these areas of inflammation?

Answer 29

Usually necrotizing granulomatous inflammation (“caseous necrosis”) Multinucleated giant cells

Question 30

what antibiotic treatments are available for TB?

Answer 30

*** Isoniazid (INH), rifampin, and pyrazinamide daily for 2 months - Then, INH and rifampin (daily, 2x or 3x weekly) for 4 mos. Ethambutol or streptomycin also used

Question 31

____________ is a bacteriostatic antimycobacterial drug

Answer 31

Ethambutol

Question 32

how long after the start of antibiotics is a patient with TB considered to be non-contagious?

Answer 32

2 weeks

Question 33

what causes Actinomycosis?

Answer 33

Caused by any of several Actinomyces species that normally inhabit the mouth

Question 34

besides the oral cavity, what other locations are susceptible to Actinomycosis?

Answer 34

Abdominal (25%), pulmonary (15%) or cervicofacial (55%) areas may be affected (most are cervicofacial/oral in location)

Question 35

_____________ Actinomycosis May follow dental extraction or untreated dental disease

Answer 35

Cervicofacial

Question 36

clinical signs of Cervicofacial Actinomycosis:

Answer 36

Diffuse swelling and erythema Draining sinus tracts “Sulfur granules”

Question 37

what composes the "sulfer granules" of Actinomycosis?

Answer 37

colonies of organisms in purulent exudate

Question 38

describe the histopathology of an Actinomycosis infection:

Answer 38

- Filamentous bacteria that form colonies - Bacterial colonies surrounded by neutrophils - Adjacent tissue may show granulomatous inflammation or granulation tissue

Question 39

what is the treatment for a patient with Actinomycosis?

Answer 39

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

Question 40

what is the clinical term for an existing skin lesion that becomes affected by impetigo?

Answer 40

“Impetiginized” - prexisting dermatitis, cuts, scratches, insect bites, etc