A lady approaches a physician for contraceptive advice. On examination, there were two symmetrical ulcers on vulva, which were well defined with firm base. Which of the following is the most likely cause:

Chancre is the primary lesion of primary syphilis. • It is most commonly found on the labium majus, labium minus, fourchette, clitoris, urethral orifice or cervix but can be found anywhere on the lower genital tract. • In 10% cases more than one primary lesion is present. • The first manifestation is a small papule which breaks to form an ulcer. • Ulcer is firm, painless with raised edges and granulomatous base. • In fact any sort of discrete relatively painless ulceration on the vulva may be primary syphilitic lesion. • Inguinal glands enlarge when the primary is on the vulva or lower vagina. • Lymph nodes are hard, shotty, painless, and do not suppurate.