What is a kissing ulcer?

A kissing ulcer is a pair of ulcers caused by an infectious agent that developed when a primary ulcer caused a secondary ulcer by spreading the infectious agent by contacting the contralateral side of the same anatomical structure. For example a chancroid ulcer on the left labium may infest the contralateral right labium through contact and cause a corresponding ulcer. The two corresponding ulcers are referred to as kissing ulcers.