2nd Lecture: Pediculosis & The Treponema (Syphilis, Yaws, Pinta) Flashcards Preview

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Flashcards in 2nd Lecture: Pediculosis & The Treponema (Syphilis, Yaws, Pinta) Deck (93)
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What are the 4 learning objectives of this lecture?

1. Cite the presentation, diagnosis, and treatment of lice infestation.
2. Explain the limitations of the "culture & Gram Stain" approach when applied to spirochete infections
3. Cite the unique structural and motile properties of spirochetes
4. Describe the three disease stages, transmission, treatment, and prevention of syphilis.


What are the 5 characteristics of the bacteriology of Treponema pallidum (Syphilis)?

1. Motile: flagellar corkscrew motion
2. Not culturable
3. Very slow growing
4. Trepenoma are too slender to Gram stain
5. Too delicate to survive outside a host


What are the three modes of transmission of Syphilis?

1. Sexually
2. Transplacentally
3. Blood-blood


What does Syphilis infect?

Infects endothelium of small blood vessels


What are the triphasic infection phases of Syphilis?

1. Primary syphilis (weeks)
2. Secondary syphilis (months)
3. Tertiary syphilis (1/3 enters the tertiary)


Discuss the primary syphilis. What are the characteristics?

Initial replication at site of infection forms an ulcer called chancre, which is painless


Discuss the secondary syphilis. What are the characteristics?

1. Macropapular rash on palms and soles
2. Moist papules on skin and mucous membrane
3. Condylomata lata: highly infectious moist lesions on genital
4. Patchy alopecia, symptoms of fever, malaise, anorexia, weight loss, headache, myalgia, lymphadenopathy


What happens to patients with secondary syphilis?

1/3 resolve, 1/3 enter latency (years), the remaining 1/3 enter tertiary syphilis


1' syphilis can be considered as localized or disseminated?



2' syphilis is different from 1' how?

Secondary syphilis is disseminated disease with constitutional symptoms such as maculopapular rash (palms and soles), condylomata lata.


How can 1' and 2' syphilis be visualized?

Using darkfield microscopy


Discuss the tertiary syphlis. What are some important characteristics?

1. 1/3 of syphilis patients enter into syphilis
2. Characterized as granulomas "gummas"
3. CNS involvement


What are the two types of CNS involvement of 3' syphilis?

1. Early meningitis (less than 6 months): low-inflammation
2. Late neurosyphilis


Discuss late neurosyphilis

1. Meningovascular syphilis
2. Parenchymal neurosyphilis
1) Tabes dorsalis
2) General paresis


What is Gummas?

chronic granulomas characteristics of 3' syphilis


(First Aid) What are the 4 important characteristics of 3' syphilis?

1. Gummas (chronic granulomas)
2. aortitis (vasa vasorum destruction)
3. Neurosyphilis (tabes dorsalis)
4. Argyll Robertson pupil


(First Aid) What is Argyll Robertson pupil?

Argyll Robertson pupil constricts with accommodation but is not reactive to light. Associated with 3' syphilis. Also, called "Prostitute's pupil"


(First Aid) What is Tabes dorsalis?

Degeneration of dorsal roots and dorsal columns, which leads to impaired proprioception and locomotor ataxia


What are the characteristics of 3' syphilis?

1. Gummas (chronic granulomas)
2. Aortitis (vasa vasorum destruction)
3. Neurosyphilis (tabes dorsalis)
4. Argyll Robertson pupil


(First Aid) What are the clinical signs of 3' syphilis?

1. Broad-based ataxia
2. Positive Romberg
3. Charot joint
4. Stroke w/o HTN


(First Aid) How can 3' syphilis be diagnosed?

1. Screen with VDRL
2. Then confirm with FTA-ABS


Can spirochetes easily cross placenta?



What is the clinical consequence of spirochetes crossing the placenta?

1. 40-50% miscarriage/stillbirth/neonatal death
2. Congenital Syphilis: survivors develop severe secondary syphilis and physical abnormalities


What is the characteristics of the immunity of syphilis?

Immunity is incomplete and late latency has some protection from reinfection


What is the characteristics of pathogenesis of syphilis?

Pathogenesis does not seem to involve toxins, primarily immune evasion.


What are the lesions you are looking for to diagnosis syphilis?

Chancre, rash, condylomata lata, patchy alopecia, CNS symptoms


What are the CNS symptoms observed in syphilis pts?

1. Meningitis
2. Gummas
3. Cardiovascular symptoms
4. Argyll-Robertson pupil


Why is it important to obtain complete history of symptoms to diagnose syphilis?

B/c it may extend over years with varied symptoms arriving and departing.


What are the two types of lab test that can be done to diagnose syphilis?

1. Microscopy
2. Serology


Discuss how you can diagnose syphilis using microscopy.

1. Swab lesions for darkfield microscopy or IF
2. Biobsy gummas for histology with silver or IF