Chancroid is a sexually transmitted disease, or STD, caused by the bacteria Haemophilus ducreyi.

What is going on in the body?

Chancroid is an STD that is spread from one person to another through vaginal, anal, or oral sex. About 3 to 10 days after exposure, a newly infected person will develop a tender, red bump on the genitals. This bump, known as a bubo, will evolve into a painful ulcer over the next 2 days. Over half the people with chancroid have more than one ulcer.

What are the causes and risks of the infection?

Chancroid is a sexually transmitted disease. Risky sexual behaviors, such as having more than one partner, increase the risk for chancroid. For some reason, men are more commonly infected with chancroid than women are. Individuals with immunodeficiency disorders, such as HIV, are at higher risk for chancroid. The risk is also higher in people who are receiving chemotherapy for cancer.