Syphilis

Primary syphilis of the penis 2

In primary syphilis, the primary lesion begins as a painless, indurated papule. There is typically 1 lesion, but multiple lesions are possible. The surface of the lesion necroses resulting in a well-circumscribed chancre with a hard base. Non-tender regional lymphadenopathy generally accompanies the primary lesion(s).

Source: Boehringer-Ingelheim