What You Should Know About the Genital Ulcer STD Chancroid

Chancroid is a sexually transmitted genital ulcer disease. It caused by the bacterium Haemophilus ducreyi. Although only vert seen in the United States, chancroid is a relatively common disease in the developing world. As with syphilis, the open sores caused by chancroid increase a person's risk of acquiring other sexually transmitted infections. In particular, these open sores increase the risk of HIV.They do this by making it easier for HIV to enter the blood stream when a person is exposed. Intact skin is a reasonable barrier for HIV, which is not spread by skin to skin contact. 

The early signs of chancroid may be mistaken for syphilis -- a small pustule becomes an ulcer, usually within 4 to 10 days after exposure. However, the ulcers generally grow to a larger size and are more painful than those ulcers associated with syphilis.

Chancroid may also lead to swelling, tenderness, and inflammation of the lymph nodes in the groin. This side effect is not associated with syphilis.

Due to its rarity, it is relatively difficult to get accurately tested for chancroid in the United States. Therefore, the CDC states that doctors can diagnose chancroid without identifying the H. ducreyi bacteria if all of the following criteria are met:

1. Someone has one or more genital ulcers
2. The ulcers, and any swelling of the lymph nodes, are consistent with the expected appearance of chancroid
3. There is no evidence of syphilis under a microscope, or by blood test (after the ulcers have been present for at least 7 days) 
4. The ulcers test negative for HSV, a far more common genital ulcer disease in the U.S.

How is Chancroid Treated?

Chancroid is treated with antibiotics. The two preferred regimens are single doses of azithromycin (1g) or ceftriaxone (250 mg, IM). There are also longer regimens available using ciprofloxacin (500 mg, 2x/ day, for three days) and erythromycin base (600 mg orally, 3x/day, for seven days) However, treatment is less effective for uncircumcised men and individuals who are HIV positive. That's why the CDC recommends that anyone undergoing treatment be examined again by a doctor 3 to 7 days after treatment begins. For most people, symptoms will start to improve within that time if treatment is working.

Similarly, because of the rarity of the disease, anyone who is suspected to have chancroid should also be tested for HIV.

Chancroid is extremely uncommon in the U.S. Although far more common in the 1940s and 50s, the number of cases declined rapidly starting in the mid 50s. There was a brief increase in the 1980s, which was likely due to the new epidemic of HIV. However, the number of cases then quickly declined until infections were rare enough to make test access difficult. In 2016, a mere 7 cases were diagnosed in the entire country, only in Alabama, California, Colorado, Massachusetts, North Carolina, and South Carolina.

When chancroid appears in the US, it is more likely to be seen in refugees or immigrants from Asia, Africa, and the Caribbean. It is also more likely to be seen in someone who has a sex partner in one of these groups. Chancroid is actually on the decline around the world. It mostly causes in areas where HIV is endemic, because the chancroid ulcers provide an easy route for infection.