a. General. Syphilis is caused by a spirochete, Treponema palladium, untreated
or inadequately treated, it will usually be manifest in three stages; primary, secondary,
and late, which may overlap or be absent altogether.
b. Primary Syphilis. The incubation period for primary syphilis is variable (10 to
90 days, with 3 weeks being usual). The first indication of primary or early syphilis is an
open sore, known as a chancre, which appears at the site of entrance of the spirochete.
The chancre may persist for from 1 to 5 weeks and heal without treatment. Diagnosis is
made at this stage by finding the spirochete in darkfield microscopic examination of
material taken from the chancre. If the chancre has only recently developed, the blood
test for syphilis will be negative at this time. The appearance of the chancre is often not
typical and cannot be relied upon as a positive diagnosis. In some cases, the chancre
may be so insignificant that it goes undetected. All patients with genital lesions of any
type should be suspected of having syphilis and should have repeated darkfield
examinations and serological tests in order to confirm or rule out this possibility.
Lesions of the lips, fingers, female breasts, or occasionally elsewhere on the body,
which fail to heal within 10 days, should be inspected as extragenital primary syphilis
and warrant repeated darkfield examinations.
c. Secondary Syphilis. Secondary lesions of early syphilis may appear in the
form of a skin eruption, accompanied by enlarged lymph glands, within a period of from
3 to 8 weeks or longer after appearance of the initial lesion. In addition or separately,
there may also be one or more of a large variety of symptoms that include lesions in the
mouth, and genitalia, condylomata (moist, flat top papules), sore throat, patchy falling of
hair, headache, malaise and fever. These secondary lesions usually disappear within
about 3 weeks. If untreated, they may reappear one or more times as relapses.
Diagnosis may be made from early lesions by darkfield examinations, but these may be
negative during the secondary stage. The serological test for syphilis (SYS) is almost
always positive during this stage.
d. Late Syphilis. Late syphilis follows secondary syphilis after a period of
latency of from 5 to 20 years. Complications of this stage may be blindness, insanity,
paralysis, vascular disease, loss of position sense, arthritis, or granulomas in any organ
or tissue of the body. Darkfield examinations of any lesions in this stage are almost
always negative; blood test is usually positive but may be doubtful or negative. The
longer the duration, the greater likelihood that the serological tests will become negative
spontaneously. The spinal fluid examination may or may not be positive. If it is
positive, the patient has central nervous system syphilis. This may go on for years
before symptoms develop. Some patients, however, may have symptoms of central
nervous system syphilis without positive spinal fluid findings.