Sexually Transmitted Diseases (STDs in Men) (cont.)

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What is syphilis?

Syphilis is an infection that is caused by a microscopic organism called Treponema pallidum. The disease can go through three active stages and a latent (inactive) stage.

In the initial or primary stage of syphilis, a painless ulcer (the chancre) appears in a sexually-exposed area, such as the penis, mouth, or anal region. Sometimes, multiple ulcers may be present. The chancre develops any time from 10 to 90 days after infection, with an average time of 21 days following infection until the first symptoms develop. Painless, swollen glands (lymph nodes) are often present in the region of the chancre, such as in the groin of patients with penile lesions. The ulcer can go away on its own after 3 to 6 weeks, only for the disease to recur months later as secondary syphilis if the primary stage is not treated.

Secondary syphilis is a systemic stage of the disease, meaning that it can involve various organ systems of the body. In this stage, therefore, patients can initially experience many different symptoms, but most commonly they develop a skin rash, frequently on the palms of the hands, that does not itch. Sometimes the skin rash of secondary syphilis is very faint and hard to recognize, and it may not even be noticed in all cases. In addition, secondary syphilis can involve virtually any part of the body, causing, for example, swollen glands (lymph nodes) in the groin, neck, and arm pits, arthritis, kidney problems, and liver abnormalities. Without treatment, this stage of the disease may persist or resolve (go away).

Subsequent to secondary syphilis, some people will continue to carry the infection in their body without symptoms. This is the so-called latent stage of the infection. Then, with or without a latent stage, which can last as long as twenty or more years, the third (tertiary) stage of the disease can develop. Tertiary syphilis is also a systemic stage of the disease and can cause a variety of problems throughout the body including:

  1. abnormal bulging of the large vessel leaving the heart (the aorta), resulting in heart problems;
  2. the development of large nodules (gummas) in various organs of the body;
  3. infection of the brain, causing a stroke, mental confusion, meningitis, problems with sensation, or weakness (neurosyphilis);
  4. involvement of the eyes leading to sight deterioration; or
  5. involvement of the ears resulting in deafness. The damage sustained by the body during the tertiary stage of syphilis is severe and can even be fatal.

How is syphilis diagnosed?

A diagnosis of the chancre (primary stage of disease) can be made by examining the ulcer secretions under a microscope. A special microscope (dark field), however, must be used to see the distinctive corkscrew-shaped Treponema organisms. Since these microscopic organisms are rarely detected, the diagnosis is most often made and treatment is prescribed based upon the appearance of the chancre. Diagnosis of syphilis is complicated by the fact that the causative organism cannot be grown in the laboratory, so cultures of affected areas cannot be used for diagnosis. Syphilis is diagnosed with a blood test even in stage 1.

For secondary and tertiary syphilis, the diagnosis is based upon antibody blood tests that detect the body's immune response to the Treponema organism.

The standard screening blood tests for syphilis are called the Venereal Disease Research Laboratory (VDRL) and Rapid Plasminogen Reagent (RPR) tests. These tests detect the body's response to the infection, but not to the actual Treponema organism that causes the infection. These tests are thus referred to as nontreponemal tests. Although the nontreponemal tests are very effective in detecting evidence of infection, they can also produce so-called false positive results for syphilis. Consequently, any positive nontreponemal test must be confirmed by a treponemal test specific for the organism causing syphilis, such as the microhemagglutination assay for T. pallidum (MHA-TP) and the fluorescent treponemal antibody absorbed test (FTA-ABS). These treponemal tests directly detect the body's response to Treponema pallidum.

Patients with secondary, latent, or tertiary syphilis will almost always have a positive VDRL or RPR, as well as a positive MHA-TP or FTA-ABS. Several months after treatment, the nontreponemal tests will generally decrease to undetectable or low levels. The treponemal tests, however, will usually remain positive for the remainder of the patient's life whether or not they have been treated for syphilis.

How is syphilis treated?

Depending on the stage of disease, the treatment options for syphilis vary as summarized in the table below. Depending on the stage of disease and the clinical manifestations, the treatment options for syphilis vary. Long-acting penicillin injections have been very effective in treating both early and late stage syphilis. The treatment of neurosyphilis requires the intravenous administration of penicillin. Alternative treatments include oral doxycycline or tetracycline. Nothing is as effective as penicillin. Patients with penicillin allergies will often undergo immonotherapy in order to tolerate penicillin to be treated for syphilis.

What should a person do if exposed to someone with syphilis?

Anyone who has been sexually exposed to an individual with the ulcer or skin rash of syphilis can potentially become infected. Persons who were exposed within 90 days preceding their partner being diagnosed with primary, secondary, or latent syphilis should be treated with one of the regimens for primary or secondary disease, even if antibody tests are negative. If the exposure occurred more than 90 days before the partner was diagnosed, the exposed individual should undergo a nontreponemal test (RPR or VDRL tests). If the test is not readily available and/or follow-up is not guaranteed, the person should be treated as for primary or secondary syphilis. Finally, long-term sex partners of people with later (greater than 1 year duration) latent infection or tertiary syphilis should be evaluated by a physician and undergo blood tests for syphilis. The decision regarding treatment should be based upon whether the person has any symptoms of primary, secondary, or tertiary syphilis and the results of their blood tests for syphilis. Final decisions on the extent of the treatment for syphilis should be made after consultation with an infectious disease specialist.

Medically Reviewed by a Doctor on 10/16/2014

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