Discussion
Syphilis is caused by the motile Gram-negative spirochete Treponema pallidum. It has been described as the “great imitator,” due to its invasive and immunoevasive nature3. It is transmitted sexually or vertically during pregnancy. In the 1990’s, syphilis made a resurgence worldwide, most prominently in men who have sex with men (MSM). In 2015, the United States case rate for primary and secondary syphilis in MSM was 221 times the rate for women and 106 times the rate for heterosexual males3. The World Health Organization (WHO) estimated that 17.7 million people between ages 15-49 had syphilis in 2012, with 5.6 million new cases yearly3.
Treponema pallidum is an obligate human pathogen, which enters the body through areas of microtrauma. Primary syphilis occurs approximately 2-3 weeks after initial infection, and is evidenced by the development of the chancre. This phase of illness may pass unnoticed, thereby enabling progression of infection4. Approximately 4-8 weeks after the primary stage, secondary syphilis presents as bacteremia associated with a widespread maculopapular rash which may involve the scalp, palms, and soles of the feet. Condyloma lata and systemic symptoms may also be present. Late latent syphilis, or tertiary syphilis, occurs in approximately 35% of untreated patients, though this is seen most commonly in resource-poor nations4. Tertiary syphilis may manifest as cardiovascular syphilis, neurosyphilis, or gummatous syphilis4.