What symptom characterizes the primary stage of syphilis?

The primary stage of syphilis is characterized by the presence of a painless chancre, which is a firm, ulcer-like sore that appears at the site of infection, typically within three weeks after exposure to the Treponema pallidum bacterium. This sore is usually singular, round, and has raised edges, often going unnoticed because of its painless nature. The development of this chancre indicates that the body is responding to the initial infection, and while it will heal spontaneously in a few weeks, the infection does not resolve without treatment.

The other options represent findings associated with different stages or complications of syphilis. A rash is more characteristic of secondary syphilis, which occurs after the primary chancre heals. Gumma is a soft tumor that typically appears in the tertiary stage of syphilis, reflecting late-stage manifestations of the disease. Deafness may occur as a congenital complication in infants born to mothers with untreated syphilis, but it is not a direct symptom of the primary stage in adults. Understanding these distinctions is crucial in diagnosing and managing syphilis effectively.