Pathogenesis (development of disease)
Ulcus molle is transmitted by the bacterium Haemophilus ducreyi mainly through sexual intercourse. The bacterium nests in small skin lesions, where papules then form that break open ulcerously and cause severe pain.
Etiology (causes)
Biographic causes
- Geographic factors – developing countries
Behavioral causes
- Drug use including sharing of drug paraphernalia.
- Sexual transmission
- Promiscuity (sexual contact with relatively frequently changing different partners).
- Prostitution
- Men who have sex with men (MSM).
- Sexual contacts in the vacation country
- Unprotected coitus
- Sexual practices with high risk of mucosal injury (e.g., unprotected anal intercourse/anal sex).
Disease-related causes
- Other sexually transmitted diseases such as syphilis.
