Chancroid ( ) is a bacterial sexually transmitted infection characterized by painful sores on the genitalia. Chancroid is a bacterial infection caused by the fastidious Gram-negative streptobacillus Haemophilus ducreyi. Chancroid is known to spread from one individual to another solely through sexual contact. However, there have been reports of accidental infection through the hand.

Signs and symptoms

thumb|Buboes in a male

These are only local and no systemic manifestations are present. The ulcer characteristically:

  • Ranges in size dramatically from 3 to 50 mm (1/8 inch to 2 inches) across
  • Is painful
  • Has sharply defined, undermined borders
  • Has irregular or ragged borders, described as saucer-shaped.
  • Has a base that is covered with a gray or yellowish-gray material
  • Has a base that bleeds easily if traumatized or scraped
  • Painful swollen lymph nodes occur in 30–60% of patients.
  • Dysuria (pain with urination) and dyspareunia (pain with intercourse) in females

About half of infected men have only a single ulcer. Women frequently have four or more ulcers, with fewer symptoms. The ulcers are typically confined to the genital region.

Chancroid, caused by H. ducreyi has infrequently been associated with cases of genital ulcer disease in the US but has been isolated in up to 10% of genital ulcers diagnosed from sexually transmitted infection (STI) clinics in Memphis and Chicago.

Infection levels are very low in the Western world, typically around one case per two million of the population (Canada, France, Australia, UK and US). Most individuals diagnosed with chancroid have visited countries or areas where the disease is known to occur frequently, although outbreaks have been observed in association with crack cocaine use and prostitution.

Chancroid is a risk factor for contracting HIV, due to their ecological association or shared risk of exposure, and biologically facilitated transmission of one infection by the other. Approximately 10% of people with chancroid will have a co-infection with syphilis and/or HIV.

Pathogenesis

Haemophilus ducreyi enters skin through microabrasions incurred during sexual intercourse. The incubation period of the infection is 10 to 14 days, after which there is progression of the disease.

Diagnosis

Variants

Some of clinical variants are as follows. 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

;Similarities

  • Both originate as pustules at the site of inoculation, and progress to ulcerated lesions
  • Both lesions are typically 1–2 cm in diameter
  • Both lesions are caused by sexually transmissible organisms
  • Both lesions typically appear on the genitals of infected individuals
  • Both lesions can be present at multiple sites and with multiple lesions

;Differences

  • Chancre is a lesion typical of infection with the bacterium that causes syphilis, Treponema pallidum
  • Chancroid is a lesion typical of infection with the bacterium Haemophilus ducreyi
  • Chancres are typically painless, whereas chancroid are typically painful
  • Chancres are typically non-exudative, whereas chancroid typically have a grey or yellow purulent exudate
  • Chancres have a hard (indurated) edge, whereas chancroid have a soft edge
  • Chancres heal spontaneously within three to six weeks, even in the absence of treatment
  • Chancres can occur in the pharynx as well as on the genitals

Prevention

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.

Antibiotics

Macrolides are often used to treat chancroid. The CDC recommendation is either a single oral dose (1 gram) of azithromycin, a single IM dose (250 mg) of ceftriaxone, oral (500 mg) of erythromycin three times a day for seven days, or oral (500 mg) of ciprofloxacin twice a day for three days. Data is limited, but there have been reports of ciprofloxacin and erythromycin resistance.

Aminoglycosides such as gentamicin, streptomycin, and kanamycin has been used to successfully treat chancroid; however aminoglycoside-resistant strain of H. ducreyi have been observed in both laboratory and clinical settings.<sup>[7]</sup> Treatment with aminoglycosides should be considered as only a supplement to a primary treatment.

Pregnant and lactating women, or those below 18 years of age regardless of gender, should not use ciprofloxacin as treatment for chancroid. Treatment failure is possible with HIV co-infection and extended therapy is sometimes required.

Prognosis

Prognosis is excellent with proper treatment. Treating sexual contacts of affected individual helps break cycle of infection.

Follow-up

Within 3–7 days after commencing treatment, patients should be re-examined to determine whether the treatment was successful. Within 3 days, symptoms of ulcers should improve. Healing time of the ulcer depends mainly on size and can take more than two weeks for larger ulcers. In uncircumcised men, healing is slower if the ulcer is under the foreskin. Sometimes, needle aspiration or incision and drainage are necessary. Some of important events on historical timeline of chancre are:

{| class="wikitable"

|-

! Year !! Event

|-

| 1852|| Leon Bassereau distinguished chancroid from syphilis (i.e. soft chancre from hard chancre)

|-

| 1890s || Augusto Ducrey identified H. ducreyi

|-

| 1900|| Benzacon and colleagues isolated H. ducreyi

|-

| 1970s|| G. W. Hammond and colleagues developed selective media

|}

References