Syphylis Dan Flashcards
What is the organism responsible for syphylis?
Treponema (genus) pallidum (species) pallidum (subspecies)
T/F
T. pallidum is a protoza
False
A spirochete
T/F
T. pallidum is microaerophilic
True
needs a small amount of O2, not too much
T/F
T. pallidum can be cultured in vitro
False
Cannot be cultured in vitro
Cannot survive outside an animal host
T/F
T. pallidum is slow growing
True
What is the organism responsible for endemic syphylis?
treponema pallidum endemicum
T/F
Syphylis is the main cause of genital ulcers in low income countries
True
In Australia what populations are most at risk of syphylis?
most new cases are in MSM
with possible exception of in NT where still high rates of indigenous syphylis
What is syphylis d’emblee
syphylis acquired by deep innoculation e.g. via needlestick - rare
Is usuallly through contact with through mucous membranes or abraded skin
T/F
All stages of Syphylis are equally infective
False
primary and secondary more than tertiery
T/F
After innoculation treponemes disseminate to local lymph nodes and internal organs within hours
True
T/F
Replication time for T pallidum is about 3 days
False
30 hours
What proportion of infected pts develop secondary syphylis?
almost 100%
What proportion of those with secondary syphylis clear spontaneously?
1/3 clear
2/3 progress to latent disease
T/F
25% of pts in latent phase syphylis have relapses of symptoms of secondary syphylis
True
What is the fate of pts with untreated latent syphylis?
1/3 Asymptomatic with negative RPR but positive specific serology (may be self cured or in RPR-ve latent phase)
1/3 Asymptomatic with positive RPR and positive specific serology (ongoing latent disease)
1/3 develop tertiary syphilis – mucocutaneous>CVS>neurosyphylis
T/F
tertiery syphylis has a mortality of 10%
False
up to 50% if untreated
How long is the latent period after contracting syphylis until symptoms of primary syphylis appear?
9-90 days
average 3 weeks
What are the features of primary syphylis?
Chancre is characteristic lesion
Painless, firm, indurated, circumscribed round/oval ulcer
sometimes >1
with non-tender rubbery regional lymphadenopathy
Typically ulcer at 3 wks, unilat LNs at 4 wks, bilat LNs at 5 wks
resolves in 1-3 months, sometimes scars
How is primary syphylis diagnosed?
Chancre is full of treponemes esp at edge - swab and dark ground microscopy is traditional but rarely performed
Can swab for fluorescence microscopy or for PCR
Usually diagnosed by serology - RPR and specific tests
- if serology negative repeat in 2 weeks
T/F
80% of primary syphylis cases will be positive for RPR
True
T/F
40% of primary syphylis cases will be positive for specific serology tests
False
90% positive
T/F
Dark field miscroscopy can be reliably performed on chancre swabs from the mouth
False
There are resident spirochetes on mucosal surfaces
can only be performe don skin chancre swabs
T/F
Dark field miscroscopy is the most sensitive and specific diagnostic test in primary syphylis
True
but rarely performed
T/F
More than one test is essential for reliable diagnosis of syphylis
True
T/F
On dark field miscroscopy T pallidum spirals around on its long axis and moves forward and backward in a characteristic way. It also bends itself into acute or obtuse angles
True
T/F
fluroesence staining of smears from swabs is an alternative to dark field microscopy
True
T/F
syphylis can be confirmed with one positive serological test
False
need either one +ve specific and one non-specific test
Or 2 +ve specific tests
Labs routinely do second test automatically if first is positive
What is the sequence of serological testing in Australia?
In Aus usually do a modern serology assay first;
EIA (enzyme immunoassay) or
CLIA (chemiluminesence immunoassay)
and if +ve lab will proceed to a conventional serology test
V. sensitive but high risk false positives (not that specific)
If +ve do conventional test;
TPPA (T. Pallidum Particle Agglutination test) or
FTA-abs (Fluorescent Treponemal Ab–absorption test)
RPR may be requested specifically
T/F
The first line diagnostic serology test for syphylis is the VDRL or RPR
False
VDRL not done anymore
RPR not used for diagnosis but can be requested in confirmed cases
What is the RPR test?
Rapid plasma reagin test for IgG and IgM antibodies to cardiolipin-lecithin-cholesterol antigen
(syphilis infection triggers the formation of anticardiolipin and other related antibodies)
T/F - regarding RPR serology;
4x decrease indicates successful treatment
True
T/F - regarding RPR serology;
A 6x increase indicates reinfection
False
4x increase indicates re-infection
T/F - regarding RPR serology;
Test becomes negative if early effective treatment received
True
In what circumstances is RPR negative and specific serology positive?
- False positive serology test or false negative RPR
- Early effective treatment of syphylis
- pt has cleared the disease spontaneously
- pt has entered an RPR-negative latent phase - possibly self-cleared but still need to treat if untreated
T/F
HIV pts may get false negative RPR test
True
T/F
All specific T. pallidum serology tests measure Abs to T. pallidum surface proteins
False
TPPA does (T Pallidum Particle Agglutination test)
also; TPHA and MHA-TP
In the FTA-abs test, Abs react with whole treponeme forming complexes
T/F
All specific T. pallidum serology tests remian positive lifeling after infection
True
unless very early treatment received
T/F
Specific T. pallidum serology tests cannot differentiate syphilis from non-venereal treponemal infection
True
What are the causes of false positive specific T. pallidum serology tests?
Autoimmune disease HIV Hypogammaglobulinaemia Older age CVS disease Lyme disease Pinta, Yaws, Other STDs (HSV)
What dilution constitutes a positive result for RPR?
In the context of a clinical suspicion of syphilis, RPR of 1:8 or above confirms the diagnosis
T/F
The papule is the classic lesion of secondary syphylis
True
What are the 3 common features of the eruptions of secondary syphylis?
They are NOT itchy
They are coppery-red
They are symmetrically distributed
T/F
secondary syphylis is a systemic illness
True
T/F
secondary syphylis occurs by dissemination of treponemes in the blood and lymphatics
True
T/F
secondary syphylis cannot occur while the primary chancre is still present
False
time from the same time as the primary lesion up to 6 months later
most commonly 3-10 wks after infection
T/F
The early latent phase is the asymptomatic period which may occur between resoultion of primary syphylis and onset of clinical signs of secondary syphylis
True
T/F
secondary syphylis affects a minority of infected individuals
False
almost all get secodnary syphylis
T/F
Circulating immune complexes are responsible for some of the clinical features of secondary syphylis
True
The prodrome of secondary syphylis involves
Fever, malaise, sore throat and generalised lymphadenopathy
True
may also be weight loss, headache (meningeal irritation), conjunctivitis, arthralgia (from periostitis), mylagia, hepatosplenomegally, mild hepatitis
o Symptoms often worse at night
T/F
generalised papulosquamous rash is the most common clinical feature of secondary syphylis
True
80%
What are the features of the rash of secondary syphylis?
rash often starts about 8 wks after infection
usually generalised papulosquamous but initially macular and become papular by 3 months
- lesions can be from 1-2mm up to 1-2 cm
- often copper-coloured
macular phase called macular syphylide
papular phase called papular syphylide
Can be polymorphic, corymbose arrangement of satellite papules around a larger central lesion
Some get a morbiliform or roseola-like (pityriasiform) eruption which is not as widespread
But always coppery-red, symmetrical and non-pruritic
Apart from the rash on the trunk and linbs what are the other skin findings of secondary syphylis?
papules/plaques on palms and soles with collarete of scale
syphylitic paronychia
Annular plaques on face or elsewhere w/ central hyperpigmentation
Moth eaten, patchy, non-scarring alopecia (5%); can also get telogen effluvium
Corona veneris – rash along hairline
Fissured papules at oral commissures
Hypopigmentred macules on neck – ‘necklace of venus’
What is lues maligna?
Rare variant of of secondary syphylis w/ disseminated necrotic ulcers resembling chancres, pt ofen systemically unwell
What are the mucosal findings in secondary syphylis?
small ulcers
Chancre redux
condylomata lata (flat toped warty papules) in anogenital area – often around 6/12 (10-20%)
mucous patches in oropharyx – superficial grey erosions which can coalesce to look like snail tracks (in up to 30%)
syphilitic sore throat – whole throat inflamed, erosions, hoarseness
T/F
about 1/3 of pts with secondary syphylis get mucosal signs
True
What is ‘Chancre redux’?
recurrence of the primary chancre at its original site in secondary syphylis
What are the systemic findings in secondary syphylis?
LNs - 50-90% get generalised lymphadenopathy
Neurological–headache, hearing loss, cranial neuropathy/ focal neurology
Eyes - photophobia, visual disturbance, uveitis
Abnormal liver enzymes
Rarely – hepatitis, gastritis, glomerulonephritis, myocarditis, joint effusions, periostitis
T/F
spirochetes may be seen in skin biopsies in secondary syphylis
True
treponemal immunostain
T/F
Pts with secondary syphylis must be assessed for occular and neurological signs
True
If present refer to ID for LP and send off CSF - nb in reality you get ID inout for every case
T/F
Should always do HIV test in pts with syphylis
True
o Also always check for HepC in MSM