Final answer:
The primary syphilitic lesion is called a chancre, which is a painless and highly infectious sore that appears at the site of syphilis bacteria entry.
Step-by-step explanation:
The primary syphilitic lesion is known as a chancre. This condition is linked to primary syphilis and is characterized by the formation of a usually firm, round, and painless sore at the site where the syphilis bacteria entered the body. This lesion is highly infectious, contains many T. pallidum cells, and is initially hard and painless before it develops into an ulcerated sore. Although it might heal on its own within two to six weeks, treatment is necessary to prevent the disease from progressing to secondary and tertiary stages. Secondary syphilis can involve a rash, cutaneous lesions, and systemic symptoms such as malaise and fever, while tertiary syphilis might lead to serious complications such as gummas, cardiovascular syphilis, and neurosyphilis.