Syphilis is primarily a sexually transmitted disease caused by the bacterium Treponema pallidum (because syphilis is in the genus Treponema, it can also be called a “treponemal disease”; however, there are other treponemal diseases that are not syphilis). It is transmitted through the mucous membranes, broken skin, and direct mother-to-child infection during pregnancy. As such, unprotected sex (anal, oral, vaginal, or any other permutation that results in the exchange of bodily fluids) increases an individual's risk of contracting the disease. Similarly, risky sexual behavior and increased number of sexual partners also increase an individual’s risk of contracting syphilis (and other sexually transmitted diseases).
Syphilis typically presents in three distinct symptomatic stages, (described below) marked by potentially long periods of symptom-free remission between stages. If left untreated, the final stage is usually ultimately fatal. However, it can take up to several decades from the point of initial infection until an individual enters the third and final phase of the disease.
As mentioned above, syphilis commonly presents with three distinct symptomatic stages. These are commonly known as Primary, Secondary, and Tertiary syphilis. Each stage is marked by its own set of typical signs and symptoms of the underlying disease.
● Primary Syphilis usually presents as a single round, painless, firm lesion called a chancre. It usually appears around the genitals or anus, but can occur elsewhere on the body. It usually appears within three weeks of the time of the initial infection. Even if left untreated, the chancre will usually heal within three to ten days.
● Secondary Syphilis usually presents as a more diffuse non-itchy rash across the skin. One of the distinct features of secondary syphilis is that this rash often can involve both the palms of the hands and the soles of the feet. Even if left untreated, this phase will also usually resolve on its own.
● Tertiary Syphilis may occur multiple decades after the initial infection, if left untreated. It can cause diffuse damage throughout the individual’s body to multiple different organ systems, from bone to skin and so forth. However, what often ends up claiming the lives of the afflicted individuals is the damage done to their brain and cardiovascular system. If there is clinical suspicion of syphilis, the individual will still require additional laboratory testing to confirm the diagnosis.
Individuals infected with syphilis can still be accurately tested even if they do not have any active symptoms suggestive of syphilis. This is done by a combination of two blood tests:
1. A nontreponemal test, such as the Venereal Disease Research Laboratory (VDRL) or Rapid Plasma Reagin (RPR) test.
2. A treponemal test, such as the Treponema pallidum Passive Particle Agglutination assay (TP-PA), Enzyme Immunoassays (EIA), Chemiluminescence Immunoassays (CIA), or rapid treponemal assays.
A positive result for both the nontreponemal and treponemal tests is required for a diagnosis of syphilis. Additionally, if there is access to drainage or fluid from an open lesion, urinary discharge, or the tissue from a lesion, darkfield microscopy can be used to look for visual confirmation of the presence of Treponema pallidum (which appear as little white spirals under the microscope, hence their alternate classification as a “spirochete” bacteria).
As dismal and dire as untreated syphilis is, the good news is that syphilis is easily treatable and curable if caught before entering the tertiary syphilis stage of the disease. The mainstay of treatment is an injection of a long-acting form of penicillin called benzathine penicillin G. Because syphilis can be transmitted directly from mother to child during pregnancy, treatment with benzathine penicillin G is highly recommended for infected pregnant women to prevent congenital syphilis in the child. There is even evidence supporting additional treatment for pregnant women. However, because of the additional risks, this issue should be discussed with the woman’s obstetrician to decide on the best treatment plan and course of action.