In the primary stage of syphilis, when does the chancre typically develop after exposure?

• A. Within 1-3 days
• B. 1-2 months after exposure
• C. 1-2 weeks after exposure
• D. 2-3 weeks after exposure

Answer: (D)

In primary syphilis, the lesion called a chancre appears after a short incubation period following exposure. The pathogen, Treponema pallidum, multiplies at the entry site and the chancre typically becomes evident about two to three weeks later. This timing is the most commonly observed window for the primary stage, making two to three weeks after exposure the best answer. Timelines that are much shorter (within days or a week or two) are too early for the infection to manifest, while a longer delay (a month or more) falls outside the usual primary-stage window and corresponds to later stages or different clinical timing.