Chancroid is a bacterial infection that is spread through sexual contact. It is caused by a type of bacteria called Haemophilus ducreyi. Chancroid is characterized by a small bump on the genital which becomes a painful ulcer. Men may have just one ulcer, but women often develop four or more. About half of the people who are infected with a chancroid will develop enlarged inguinal lymph nodes, the nodes located in the fold between the leg and the lower abdomen. In some cases, the nodes will break through the skin and cause draining abscesses. The swollen lymph nodes and abscesses are often called buboes.
Chancroid is caused by the bacterium Haemophilus ducreyi and results in painful, superficial ulcers, often with regional lymphadenopathy.
The infection is found in many parts of the world, such as Africa and southwest Asia. Very few people are diagnosed in the United States each year with this infection. Most people in the United States who are diagnosed with chancroid got the disease outside the country in areas where the infection is more common.
Within 1 day to 2 weeks after becoming infected, a person will get a small bump on the genitals. The bump becomes an ulcer within a day after it first appears. The ulcer:
- Ranges in size from 1/8 inch to 2 inches (3 millimeters to 5 centimeters) in diameter
- Is painful
- Is soft
- Has sharply defined borders
- Has a base that is covered with a gray or yellowish-gray material
- Has a base that bleeds easily if it is banged or scraped
- About one half of infected men have only a single ulcer. Women often have 4 or more ulcers. The ulcers appear in specific locations.
Common locations in men are:
- Groove behind the head of the penis
- Shaft of the penis
- Head of the penis
- Opening of the penis
In women, the most common location for ulcers is the outer lips of the vagina (labia majora). "Kissing ulcers" may develop. Kissing ulcers are those that occur on opposite surfaces of the labia. Other areas, such as the inner vagina lips (labia minora), the area between the genitals and the anus (perineal area), and the inner thighs may also be involved. The most common symptoms in women are pain with urination and intercourse. The ulcer may look like the sore of primary syphilis (chancre). About one half of the people who are infected with a chancroid develop enlarged lymph nodes in the groin. In one half of people who have swelling of the groin lymph nodes, the nodes break through the skin and cause draining abscesses. The swollen lymph nodes and abscesses are also called buboes.
From bubo pus or ulcer secretions, H. ducreyi can be identified using special culture media; however, there is a <80% sensitivity. PCR-based identification of the organisms is available, but none in the United States are FDA-cleared. Simple, rapid, sensitive and inexpensive antigen detection methods for H. ducreyi identification are also popular. Serologic detection of H. ducreyi uses outer membrane protein and lipooligosaccharide. Most of the time, the diagnosis is based on presumptive approach using the symptomatology which in this case includes multiple painful genital ulcers. Instead of laboratory diagnosis, a presumptive clinical diagnosis can be made if all of the following are present:
- One or more painful genital ulcers.
- Clinical findings, the appearance of genital ulcers, and any presenting regional lymphadenopathy are consistent with chancroid.
- No evidence of Treponema pallidum infection by darkfield microscopy of the exudate or by a serologic test performed at least 7 days after the onset of ulcers.
- A Herpes simplex virus PCR test or culture performed on the exudate is negative.
Despite many distinguishing features, the clinical spectrums of following diseases may overlap with chancroid:
- Primary syphilis
- Genital herpes
- Practical clinical approach for this STI as Genital Ulcer Disease is to rule out top differential diagnosis of Syphilis and Herpes and consider empirical treatment for Chancroid as testing is not commonly done for the latter.
Chancroid infections can be treated with antibiotics, including azithromycin, ceftriaxone, ciprofloxacin, and erythromycin. Large lymph node swellings need to be drained, either with a needle or local surgery.
Chancroid can get better on its own. Some people have months of painful ulcers and draining. Antibiotic treatment often clears up the lesions quickly with very little scarring.
Chancroid spreads in populations with high sexual activity, such as prostitutes. Use of condom, prophylaxis by azithromycin, syndromic management of genital ulcers, treating patients with reactive syphilis serology are some of the strategies successfully tried in Thailand. Also, treatment of sexual partners is advocated whether they develop symptoms or not as long as there was unprotected sexual intercourse with the patient within 10 days of developing the symptoms.
NIH genetic and rare disease info
Chancroid is a rare disease.