Syphilis
Lamis Ibrahim
James W. Myers
INTRODUCTION
Syphilis is a systemic disease caused by the spirochete Treponema pallidum subspecies pallidum. It has been known as the “Great Imitator.”
EPIDEMIOLOGY
Modes of transmission:
Sexual
Vertical (causing congenital syphilis)
Rarely, by blood transfusion.
Average age of diagnosis is 15 to 30 in females and 15 to 54 in males.
Highest incidence in USA is in Southeast and Southwest regions.
Incubation period: about 3 weeks (range 10 to 90 days).
PATHOGENESIS
Main underlying pathology is endarteritis obliterans.
Starts with local inoculation at site of contact, then erosion→ulcer. It then spreads to lymph nodes and hematogenously→immune complex formation→systemic manifestations and then goes into latent period and then tertiary syphilis if untreated.
Spontaneous clearing can occur in about 2/3 of people without treatment.
CLINICAL MANIFESTATIONS
Syphilis passes through four stages: primary, secondary, latent, and tertiary.
Primary syphilis: chancre or ulcer stage
Appears 10 to 90 days after exposure
Usually single, painless ulcer
Indurated with clean base
May be multiple, especially in human immunodeficiency virus (HIV) patients
“Kissing” lesions can occur on opposing labial surfaces
Usually seen over genital areas (penis, labia, cervix)
Extragenital areas: lips, anal and perianal areas
Regional lymph nodes may become enlarged, unilateral or bilateral, firm and painless, mobile, with no overlying skin changes
May go unnoticed and can heal spontaneously in 2 to 8 weeks
Patient is highly infectious in this stage.
Secondary syphilis: occurs 2 to 18 weeks after contact
Presents with systemic symptoms
Fever, malaise, decreased appetite
Generalized lymphadenopathy
Rash: maculopapular, may be pustular. It starts in the trunk and then spreads, to involve palms and soles. It is usually symmetrical, nonpruritic, and painless.
Mucocutaneous lesions.
Condyloma lata (papilloma-like heaped-up lesions).
Less common manifestations: alopecia, uveitis, retinitis, meningitis, osteitis,, hepatitis, glomerulonephritis
Also highly infectious stage!
LATENT SYPHILIS
Early latent is within 1 year of infection.
Twenty-five percent can have relapses during this period.
Early latent period is extended to 4 years for pregnant women.
Late latent: >1 year after infection
Patients are considered noninfectious.
Evaluate for clinical evidence of tertiary disease and syphilitic ocular disease.
The diagnosis is made by serology. The nontreponemal test may revert to normal, but the treponemal tests usually remain positive.
CSF exam needed if there are neurologic or ophthalmologic signs or symptoms, evidence of active tertiary disease such as aortitis or gumma, or treatment failure (defined as failure of a fourfold decline in rapid plasma reagin (RPR) titer 6 months after treatment), HIV-infected persons with late latent or of unknown duration.
TERTIARY SYPHILIS
3 to 10 years after infection
Gummas: granulomatous-like, seen mainly of the skin, but can involve, nose, palate, liver, spleen, bone (palate perforations, saddle-shaped nose)
Cardiovascular: aortitis→aortic aneurysm, aortic regurgitation, 10 to 30 years after infection
Neurologic: can be meningovascular or parenchymal
Meningovascular
May present as a stroke; usually 4 to 7 years after infection
Parenchymal disease usually appears later.
General paresis (deterioration in cognitive function and psychiatric symptoms then progresses to neurologic signs like pupillary problems, hypotonia, weakness, tremors).
Tabes dorsalis starts with lightning pains of the lower extremities, followed by decreased sensation and progressive ataxia, impaired position, and vibration sensation. Up to 50% of patients have Argyll Robertson pupil (small, irregular pupils that are unreactive to light but react to accommodation). Later patients may present with visceral problems that mimic an acute abdomen.
Note that central nervous system (CNS) involvement can occur during any stage and can be asymptomatic or present with cognitive impairment, motor or sensory deficits, ophthalmologic or auditory problems, cranial nerve palsies, meningitis, syphilitic eye disease (uveitis, iritis, optic neuritis, neuroretinitis).
Obtain CSF examination and serology on all suspect cases.
CSF findings in neurosyphilis include pleocytosis, elevated protein, decreased glucose, or a reactive CSF Venereal Disease Research Laboratory (VDRL).
DIAGNOSIS
Direct Visualization of the Spirochete
Dark field microscopy: gold standard for diagnosis in primary syphilis
Performed on a transudate from a chancre, mucocutaneous lesion of secondary syphilis or an aspirate of lymph nodes
Sensitivity, 74% to 86%; specificity, 86% to 100%
Considered to be truly negative if there are three negative samples
DFA has 73% to 100% sensitivity; specificity, 89% to 100%
PCR: not readily available
Serology: Nontreponemal and Treponemal
Nontreponemal: VDRL/RPR; more sensitive, less specific
Can be negative in primary syphilis in up to 30% but almost always positive in secondary syphilis
Fourfold changes are considered significant
Can be used to monitor response to therapy
Correlates with disease activity, but titers can persist for a long period of time and define a condition known as a “serofast reaction.”
In primary syphilis, they usually become negative at 12 months, and 24 months in secondary syphilis after appropriate treatment. If not, it may indicate persistent infection or a false positive.
Causes of false-positive results: physiologic (pregnancy, old age), infections (HIV, herpes viruses infections, hepatitis, mycoplasma, TB, leprosy, leptospirosis, Lyme disease), vaccination, autoimmune disease, chronic liver disease, intravenous drug usage (IVDU), malignancy, and others.Related posts:
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