Chancroid is a sexually transmitted disease caused by the bacteria Haemophilus ducreyi, which causes painful genital sores.

In developed countries, chancroid is rare, but it is a common cause of genital ulcers throughout much of the developing world, where it may be acquired by men from prostitutes. Because chancroid causes genital sores, people who have it are more likely to become infected with and to spread human immunodeficiency virus (HIV).

Symptoms

Symptoms begin 3 to 7 days after infection. Small, painful blisters form on the genitals or around the anus and rapidly rupture to form shallow sores. These sores may enlarge and run together. The lymph nodes in the groin may become tender, enlarged, and matted together, forming collections of pus (abscesses) called buboes. The skin over the abscess may become red and shiny and may break down and discharge pus from the lymph nodes onto the skin. Sores may form in other areas of the skin.

Diagnosis and Treatment

Doctors suspect chancroid in people with genital sores that have no obvious cause. Tests for chancroid are not readily available, but blood tests may be done to exclude other causes.

Several antibiotics are effective for chancroid. The following may be used:

• Ceftriaxone in a single injection
• Azithromycin taken by mouth in a single dose
• Ciprofloxacin taken by mouth for 3 days
• Erythromycin taken by mouth for 7 days

Last full review/revision October 2008 by J. Allen McCutchan, MD, MSc