Genital herpes ulcers. Ulcers from the rupture of herpetic vesicles on the penis of a man from Africa with the sexually transmitted disease genital herpes. This is an infection by the herpes simplex virus type 2 (HSV-2) that causes clusters of small vesicles to appear on the genitalia. They are accompanied by headaches and fevers. There is no cure for the viral infection, but any infection of the ulcers is treated with antibiotic drugs. In the tropics, severe cases of sexually transmitted diseases (STDs) are relatively common.