Download Syphilis.

2.6.1.8. Lecture nr.8 – Syphilis.- 2 hours
Background
Syphilis is a chronic systemic venereal disease with multiple clinical
presentations.
Syphilis is caused by Treponema pallidum. T. pallidum is a very small, spiral
bacterium (spirochete) whose form and corkscrew rotation motility can be observed
only by dark-field microscopy.
Syphilis is transmitted in 2 ways, either from intimate contact with infectious
lesions (most common sexually) or blood transfusions (blood collected during early
syphilis), or it is transmitted transplacentally from an infected mother to her fetus.
Therefore there are 2 distinct forms of syphilis: acquired and congenital.
Acquired syphilis is characterized by episodes of active disease (primary,
secondary, tertiary stages) interrupted by periods of latency (latent syphilis).
Pathophysiology
In acquired syphilis, the organism rapidly penetrates intact mucous membranes
or microscopic dermal abrasions and, within a few hours, enters the lymphatics and
blood to produce systemic infection. Regardless of the stage of disease and location
of lesions, 2 histopathologic hallmarks of syphilis have been noted including
obliterative endarteritis and plasma cell–rich mononuclear infiltrates.
The mononuclear infiltrates reflect a delayed-type hypersensitivity response to T
pallidum, and in certain individuals with tertiary syphilis, this response by sensitized
T lymphocytes and macrophages results in gummatous ulcerations and necrosis.
Immunity to syphilis is incomplete.
Frequency
Syphilis remains prevalent in many developing countries and in some areas of
North America, Asia, and Europe, especially Eastern Europe.
Acquired syphilis stages defined
Untreated syphilis may pass through three stages: primary, secondary and
tertiary.
Highly infectious syphilis includes the early forms of syphilis – stages of
primary, secondary, and early latent syphilis of less than 2 year’s duration.
Less infectious syphilis includes late forms of syphilis – tertiary syphilis
(cardiovascular, neurosyphilis, gummatous) and late latent syphilis more than of 2
years duration.
Primary syphilis
From 10-90 days after exposure (incubation), a primary lesion, the chancre,
develops at the site of initial contact.
The chancre is characterized by a cutaneuos ulcer or erosion, is acquired by
direct contact with an infectious lesion of the skin or the moist surface of the mouth,
anus, or vagina.
Painless, hard, discrete regional lymphadenopathy occurs in 1 to 2 weeks; the
lesions never coalesce or suppurate unless there is a mixed infection. Limphangitis is
the third symptom of primary triad.
Without treatment the chancre heals with scarring in 4 to 8 weeks, that is total
duration of primary syphilis.
Secondary syphilis
Secondary syphilis is characterized by muco-cutaneuos lesions, a flu-like
syndrome, and generalized adenopathy.
The clinical signs of the secondary stage begin approximately 6 weeks after the
chancre appears and last for 2 to 10 weeks. The following episodes (recurrent
secondary syphilis) can occur within 2-3 years (duration of secondary syphilis).
The cutaneous and mucosal lesions are varied.
The rash is usually non-itching, bilateral and symmetric.
Tertiary syphilis
The lesions of benign tertiary syphilis usually develop within 3-10 years of
infection. The typical lesion is a gumma or tuberculum. Tertiary erythema is the third
cutaneous lesion of tertiary syphilis. CNS involvement may occur, with presenting
symptoms representative of the area affected.
Latent syphilis
A patient has latent disease if a positive serologic result is discovered without
evidence of active disease. By convention, early latent syphilis is of 2 years or less
and late latent syphilis is more than 2 years duration. The periods of 2 years were
established to help predict a patient’s chance of relapsing with signs of secondary
infectious syphilis.
Congenital syphilis
T. pallidum can be transmitted by an infected mother to the fetus in utero. T.
pallidum can cross the placenta at 4th month during pregnancy. Adequate therapy of
the infected mother before the sixteenth week of gestation usually prevents infection
of the fetus. The manifestations of untreated congenital syphilis can be divided into
those that are expressed prior to age 2 years (early congenital syphilis) or after age of
2 years (late congenital syphilis).
Congenital syphilis – early manifestations
Early signs and symptoms include development of maculopapular rash and
desquamating erythema of the palms, soles and skin around the mouth and anus
(Hochzinger’s diffuse papulous infiltration); osteochondritis; syphilitic pemphigus;
syphilitic rhinitis, hepatosplenomegaly; lymphadenopathy; depressed linear scars
(Parrot-Robinson-Fournier lines).
Congenital syphilis – late manifestations
Late signs and symptoms are rare and, if encountered, usually involve
complications including interstitial keratitis, cranial nerve VIII deafness, corneal
opacities, and/or recurrent arthropathy.
Basic Lab Studies
 Dark-field microscopy is essential in evaluating moist cutaneous lesions;
 In suspected acquired syphilis, perform nontreponemal serology screening
using Venereal Disease Research Laboratory (VDRL) test, rapid plasma reagin (RPR)
test or Bordet-Wassermann test – these are screening test;.
 Then, test sera yielding a positive reaction by the Treponema pallidum
hemagglutination assay (TPHA), fluorescent treponemal antibody-absorption (FTAABS) test, or microhemagglutination assay Treponema pallidum (MHA-TP) test –
these are confirmatory tests.
Syphilis treatment
Penicillin is the mainstay of treatment, the standard by which other modes of
therapy are judged, and the only therapy that has been used widely for neurosyphilis,
congenital syphilis, or syphilis during pregnancy.
Tetracycline, erythromycin, and ceftriaxone are recommended only as
alternative treatment regimens in patients allergic to penicillin.
Follow-up (further outpatient care)
Patients with treated primary or secondary syphilis perform quantitative VDRL
testing at 1, 3, 6, and 12 months following treatment. If all clinical and serologic
examinations remain satisfactory for 2 years following treatment, the patient can be
reassured that cure is complete, and no further follow-up care is needed.
Patients with latent syphilis perform quantitative reagin testing for up to 2
years.
Patients with benign tertiary or cardiovascular syphilis should be observed by
the physician for the rest of their lives to monitor for complications.
Patients with neurosyphilis (both symptomatic and asymptomatic): examine the
CSF (cell count, protein, reagins titer) every 3-6 months for 3 years or until CSF
findings return to normal.