Lec. 2 Pediculosis and the Treponema Flashcards by Justin Faulkner

Where are the three main sites for lice to be found?

Head
Body
Pubic hair

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Name the louse present on the scalp…

Pediculus humanus capitis

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Name the louse present on the body/clothing…

Pediculus humanus corporis

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Name the louse present in pubic hair…

Pthirus pubis

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What are the classic presentations for pediculus humanus capitis (head lice)?

Schoolgirls sharing hair accessories

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What are the classic presentations for pediculus humanus corporis (body lice)?

Homeless person

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What are the classic presentations for pthirus pubis (pubic lice)?

Sexually promiscuous

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What is the treatment for Pedicures humanus capitis (head lice)?

Nit combing
Topical insecticide
Hot wash all closing and linens
Check family and classmates

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What is the treatment for Pedicures humanus corporis (body lice)?

Refer for services
Improve hygiene
discard clothing/wash plus insecticide treatment

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What is the treatment for Pthirus pubis (pubic lice)?

Hot wash all clothing and linens
Shave pubic hair
Check partners and children

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What can pediculus humanus corporis (body lice) transmit?

Typhus
Trench fever
Relapsing fever

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Why is Treponema palladium (syphilis) not culturable?

Too slender to gram stain
too delicate to survive outside a host
very slow growing

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How is Treponema palladum (syphilis) transmitted?

Intimate contact

Sex—very low infectious dose
Transplacental
blood-blood (rare)

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What does treponema palladum (syphilis) infect?

endothelium of small blood vessels

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Describe primary syphilis…

Replication at site of infection with the formation of an ulcer initiating bacteremia

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A patient presents with a macropapular rash on his palms and soles, moist papillose on skin and mucous membranes, condylomata late, patchy alopecia (hair loss), low grade fever, malaise, anorexia, weight loss, headache, myalgia and lymphadenopathy. Which phase of a syphilis infection does this patient most likely have?

Secondary syphilis

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What is the prognosis for secondary syphilis?

1/3 resolve, 1/3 enter latency, 1/3 enter tertiary syphilis

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Granulomas syphilis with CNS involvement is what phase of syphilis?

Tertiary

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What organs does the granulomas syphilis most often affect?

granulomatous lesions (“gummas”) w/ rubbery, necrotic center. Primarily liver, bones, testes

What is the time line for cardiovascular syphilis to develop and what affects does it have?

> 10yrs aneurysm of ascending aorta caused by chronic inflammation of vasa vasorum

What are the 2 CNS conditions seen in tertiary syphilis and what are the timelines for each?

Early meningitis–seen around 6months–low inflammation

Late neurosyphlis– Meningovascular syphilis–damage to blood vessels of meninges, brain, spinal cord

Parenchymal neurosyphilis: Tabes dorsalis: damage to spinal cord → impaired sensation, wide-based gait

Disruption of doral roots → loss of pain and temperature sensation, areflexia

General paresis: damage to cortical brain tissue → dementia

What is meningovascular syphilis and when does it occur?

Damage to blood vessels of meninges, brain, spinal cord occurs late in tertiary phase

What are the 3 abnormalities seen in Parenchymal neurosyphilis?

1) Tabes dorsalis–damage to spinal cord- impaired sensation, wide-based gait
2) disruption of dorsal roots- loss of pain and temperature sensation and areflexia
3) general paresis- damage to cortical brain tissue–dementia

When syphilis, a spirochete, crosses the placenta, what can occur?

40-50% miscarriage/stillbirth/neonatal death

Congenital syphilis– survivors develop severe secondary syphilis and physical abnormalities

What is the relationship of HIV to syphilis?

Ulcerations of syphilis facilitate HIV infection HIV immunosuppression accelerates syphilis course, and reduces efficacy of treatment

What is found on physical exam when a patient presents with primary syphilis?

Time course is about 3 wks Chancres are raised, red, firm, buttonlike structure up to several cm, heal in 4-8wks, Not painful unless superinfected

What is found on physical exam when a patient presents with secondary syphilis?

- begins 4-10wks after primary, peaks 3-4mo after infection - May be subtle - First-round rash is bilaterally symmetrical, with generalized nontender lymphadenopathy, round pink spots 5-10mm. - Second batch of lesions appears days or weeks later, palms&soles, become necrotic -Patchy alopecia Condylomata lata: -Reddish-brown papular lesions on the penis or anogenital area -Can coalesce into large elevated plaques up to 2-3 cm in diameter -Lesions usually progress from red, painful, and vesicular to “gun metal grey” -Sometimes confused with venereal warts Mild constitutional symptoms: malaise, headache, anorexia, nausea, aching pains in the bones, and fatigue, fever and neck stiffness Syphilitic meningitis

What can Secondary syphilis sometimes be confused with?

Venereal warts

What is found on physical exam when a patient presents with tertiary syphilis?

3-10yr after infection, years of inflammation - Gumma. Bone: deep boring pain worse at night. Skin: hyperpigmented circle. Often on lower leg, asymmetic, few grouped close - Liver - jaundice - Cardiovascular syphilis - Meningovascular syphilis - Parenchymal neurosyphilis

Describe Meingovascular syphilis...

5-10 years after infection Endarteritis affects small blood vessels of the meninges, brain, and spinal cord CNS vascular insufficiency or stroke

Describe parenchymal neurosyphilis..

15-20 years after primary infection Parenchymal CNS invasion by T. pallidum General Paretic syphilis: widespread parenchymal invasion that causes individual cell death and brain atrophy. Tabes dorsalis: damage to the sensory nerves in dorsal roots, ataxia and loss of pain sensation, proprioception, deep tendon reflexes, Deep ulcers of the feet Dementia

Describe cardiovascular syphilis...

aorta or other major arterial scarring; diastolic murmur with a tambour quality, secondary to aortic dilation with valvular insufficiency.

Describe the first round of First-round rash seen in secondary syphilis..

rash is bilaterally symmetrical, with generalized nontender lymphadenopathy, round pink spots 5-10mm.

Describe the Second batch of lesions seen in secondary syphilis...

appears days or weeks later, palms&soles, become necrotic

What is Condylomata lata seen in secondary syphilis?

- Reddish-brown papular lesions on the penis or anogenital area - Can coalesce into large elevated plaques up to 2-3 cm in diameter - Lesions usually progress from red, painful, and vesicular to “gun metal grey” - Sometimes confused with venereal warts

What is the hallmark for neurosyphilis? describe it...

Argyll-Robertson pupil | -one or both pupils fails to constrict in response to light, but does constrict to focus on a near object

What imaging studies would be order for syphilis and what is each looking for?

CT for gummas Chest radiograph, angiograph for cardiovascular syphilis CT and MRI for neurosyphilis

Why would a lumbar puncture be performed on a patient with syphilis?

neurosyphilis or syphilis+HIV: VDRL, cell count, protein PCR for evidence of past infection

What is Reagin used for when evaluating a patient with the possibility of having syphilis?

Nonspecific antibodies detectable by flocculation tests with cardiolipin (VDRL or RPR)

How does one confirm the diagnosis of syphilis using serology?

Confirm positive/equivocal results with treponeme-specific tests - fluorescent treponemal antibody-absorption (FTA-ABS) - quantitative VDRL/RPR - microhemagglutination assay T pallidum (MHA-TP) - T. pallidum hemagglutination (TPHA) - T. pallidum particle agglutination (TPPA)

What is going to replace both dark field and flocculation for serology in the next five years?

NAAT

What tests should be performed when an individual test positive for syphilis?

A full panel of STD tests

Describe the histology of syphilis...

- Endarteritis caused by binding of spirochetes to endothelial cells mediated by host fibronectin - Plasma-cell-rich infiltrate: delayed hypersensitivity to T. pallidum, leads eventually to gummatous ulcerations/necrosis

What is the most effective treatment for primary and secondary syphilis?

single injection of benzathine penicillin G

What are the alternative/less effective treatments for syphilis?

Long-term doxycycline Erythromycin Ceftriaxone

What should a patient expect 8-24h after treatment of syphilis?

Jarisch-Herxheimer reaction--flulike symptoms

What is the tropical disease of overcrowding and poor sanitation, spread by direct contact with cutaneous lesions, has three-phases of disease like syphilis but without neuro or cardio involvement, test positive for RPR+ and VDRL+ and is treated with penicillin?

Yaws--treponema pertenue