What is chancroid?

Chancroid is an infection caused by the bacterium Hemophilus ducreyi, which is passed from one sexual partner to another. It begins in a sexually exposed area of the genital skin, most commonly the penis and vulva (the female external genital organs including the labia, clitoris, and entrance to the vagina). Chancroid starts out as a tender bump that emerges 3 to10 days (the incubation period) after the sexual exposure. The cells of the tissue that form the bump then begin to die, and the bump becomes an ulcer (an open sore) that is usually painful. Often, there is an associated tenderness and swelling of the glands (lymph nodes) in the groin that normally drain lymph (tissue fluid) from the genital area; however, the painful ulcer and tender lymph nodes occur together in only about one-third of infections. Chancroid is common in developing countries.

Diagnosis of chancroid

A clinical diagnosis of chancroid (which is made from the medical history and physical examination) can be made if the patient has one or more painful ulcers in the genital area and tests are negative for syphilis or herpes. (The word chancroid means resembling a chancre, the genital ulcer that is caused by syphilis. Chancroid sometimes is called soft chancre to distinguish it from the chancre of syphilis that feels hard to the touch. The ulcer of chancroid also is painful, unlike the ulcer of syphilis that is painless.) The diagnosis of chancroid can be confirmed by a culture of the material from within the ulcer for the bacterium Hemophilus ducreyi. The clinical diagnosis justifies the treatment of chancroid even if cultures are not available.

Treatment of chancroid

Chancroid is almost always cured with a single oral dose of 1 gm of azithromycin (Zithromax) or a single injection of ceftriaxone (Rocephin). Alternative medications are ciprofloxacin (Cipro), 500 mg taken twice per day by mouth for three days, or erythromycin, 500 mg taken three times per day by mouth for 7 days. Whichever treatment is used, the ulcers should improve within 7 days. If no improvement is seen after treatment, the patient should be reevaluated for causes of ulcers other than chancroid. HIV-infected individuals are at an increased risk for failing treatment for chancroid and should be observed closely to assure that the treatment has been effective.

What should a person do if exposed to someone with chancroid?

A health care provider should evaluate anyone who has had sexual contact with a person with chancroid. Whether or not exposed individuals have an ulcer, they should be treated. Moreover, if the contact was 10 days or less before the onset of their partner's ulcer, they should be treated.