SYPHILIS
Syphilis is a sexually transmitted disease caused by the bacterium Treponema
pallidum. It is often called “the great imitator” because many of its signs
and symptoms are indistinguishable from those of other diseases. In the United
States, syphilis occurs mainly in women 20 to 24 years of age and in men 35 to
39 years of age. In the first decade of the 21st century, reported syphilis
cases have increased 2% to 5% annually. More than half of the reported cases
occur in men who have sex with men.
The
primary syphilitic lesion, a chancre, appears at the primary site of
inoculation without other symptoms after an incubation period of 6 to 90 days
(mean 21 days). In most cases, it occurs as a single lesion on the penis, but
more than one chancre may be present. The chancre begins as a papule that later
erodes. A grayish yellow and sometimes slightly hemorrhagic crust may be
present on the surface of the erosion. The smooth base is usually moist, clean,
and red. A serous exudate can be easily expressed. The classic chancre,
uncomplicated by secondary infection, has a smooth, regular border that is
neither rolled nor ragged. It represents an erosion of the skin surface rather
than a deeper ulceration, and consequently the lesion heals without scar
formation. The palpable induration is a result of vascular alterations and
lymphocyte infiltration.
Chancres
pursue a slow, indolent course that is characteristically pain free and
accompanied in more than two thirds of cases by inguinal lymphadenopathy. As
spirochetes migrate into the body, the chancre heals gradually (and without
treatment) over 3 to 6 weeks.
When
syphilis occurs concurrently with other sexually transmitted diseases or infections,
the chancre may lack characteristic features. In such cases, the primary penile
lesion may be erroneously diagnosed as chancroid, superficial abscess, or simple
abrasion. Chancres can also occur ventrally on the frenulum and appear as
small, atypical erosions. A presentation with phimosis with rubbery induration
of the foreskin or as other atypical lesions should be investigated for
syphilis. Intraurethral chancres, often manifesting as edema at the urethral
meatus, can be misdiagnosed as mild non-specific urethritis.
The
definitive diagnosis rests on the dark-field demonstration of the spirochete Treponema
pallidum in the serum exudate from the primary lesion or from aspirated
fluid from an indurated lymph node. Serologic tests (rapid plasma reagin [RPR],
Venereal Disease Research Laboratory [VDRL], fluorescent treponemal
antibody-absorption test [FTA-ABS]) become positive only when antibodies are
produced and become detectable several days or weeks from the appearance of the
chancre. Worthy of its title as the “great imitator,” syphilis may begin after
direct inoculation into the vascular or lymphatic circulation without
development of a primary skin lesion.
Syphilis
is easily cured in the primary stage, but it is imperative to recognize and to
properly treat syphilis early
rather than to allow it to further evolve into its more refractory secondary
and tertiary stages. Skin rash and mucous membrane lesions characterize the
secondary stage of syphilis. The rash appears anywhere on the body and usually
does not cause itching. Characteristically, it is rough, red, or reddish brown
and occurs on the palms of the hands and the bottoms of the feet. Sometimes the
rash is faint and barely noticeable. Additional symptoms may include fever,
lymphadenopathy, sore throat, patchy hair loss, headaches, weight loss, muscle aches, and
fatigue. Secondary syphilis will also resolve without treatment. Tertiary or
latent syphilis can last for years. The late stages of syphilis can appear 10
to 20 years after the infection was first acquired. In late syphilis, damage to
internal organs, including the brain, nerves, eyes, heart, blood vessels,
liver, bones, and joints is possible. Signs and symptoms include difficulty
coordinating muscle movements, foot drop, paralysis, numbness, gradual
blindness, dementia, and death.
