Chancroid

Chancroid
A chancroid lesion on penis
Specialty Infectious disease Edit this on Wikidata

Chancroid (/ˈʃæŋkrɔɪd/ SHANG-kroyd) (also known as soft chancre[1] and ulcus molle[2]) is a bacterial sexually transmitted infection characterized by painful sores on the genitalia. Chancroid is known to spread from one individual to another solely through sexual contact. While uncommon in the western world, it is the most common cause of genital ulceration worldwide.

Signs and symptoms

Buboes in a male

These are only local and no systemic manifestations are present.[3] The ulcer characteristically:

  • Ranges in size dramatically from 3 to 50 mm (1/8 inch to two inches) across
  • Is painful
  • Has sharply defined, undermined borders
  • Has irregular or ragged borders
  • 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 occurs in 30 to 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 initial ulcer may be mistaken as a "hard" chancre, the typical sore of primary syphilis, as opposed to the "soft chancre" of chancroid.

Approximately one-third of the infected individuals will develop enlargements of the inguinal lymph nodes, the nodes located in the fold between the leg and the lower abdomen.

Half of those who develop swelling of the inguinal lymph nodes will progress to a point where the nodes rupture through the skin, producing draining abscesses. The swollen lymph nodes and abscesses are often referred to as buboes.

Males

Females

Causes

Chancroid is a bacterial infection caused by the fastidious Gram-negative streptobacillus Haemophilus ducreyi. It is a disease found primarily in developing countries, most prevalent in low socioeconomic groups, associated with commercial sex workers.

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 STD clinics in Memphis and Chicago.[4]

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

H. ducreyi enters skin through microabrasions incurred during sexual intercourse. A local tissue reaction leads to development of erythomatous papule, which progresses to pustule in 4–7 days. It then undergoes central necrosis to ulcerate.[5]

Diagnosis

Variants

Some of clinical variants are as follows.[5]

VariantCharacteristics
Dwarf chancroidSmall, superficial, relatively painless ulcer.
Giant chancroidLarge granulomatous ulcer at the site of a ruptured inguinal bubo, extending beyond its margins.
Follicular chancroidSeen in females in association with hair follicles of the labia majora and pubis; initial follicular pustule evolves into a classic ulcer at the site.
Transient chancroidSuperficial ulcers that may heal rapidly, followed by a typical inguinal bubo.
Serpiginous chancroidMultiple ulcers that coalesce to form a serpiginous pattern.
Mixed chancroidNonindurated tender ulcers of chancroid appearing together with an indurated nontender ulcer of syphilis having an incubation period of 10 to 90 days.
Phagedenic chancroidUlceration that causes extensive destruction of genitalia following secondary or superinfection by anaerobes such as Fusobacterium or Bacteroides.
Chancroidal ulcerMost often a tender, nonindurated, single large ulcer caused by organisms other than Haemophilus ducreyi; lymphadenopathy is conspicuous by its absence.

Laboratory findings

From bubo pus or ulcer secretions, H. ducreyi can be identified. PCR-based identification of organisms is available. Simple, rapid, sensitive and inexpensive antigen detection methods for H. ducreyi identification are also popular. Serologic detection of H. ducreyi is and uses outer membrane protein and lipooligosaccharide.

Differential diagnosis

CDC's standard clinical definition for a probable case of chancroid
# Patient has one or more painful genital ulcers. The combination of a painful ulcer with tender adenopathy is suggestive of chancroid; the presence of suppurative adenopathy is almost pathognomonic.
  1. No evidence of Treponema pallidum infection by darkfield microscopic examination of ulcer exudate or by a serologic test for syphilis performed greater than or equal to 7 days after onset of ulcers and
  2. Either a clinical presentation of the ulcer(s) not typical of disease caused by herpes simplex virus (HSV) or a culture negative for HSV.

Despite many distinguishing features, the clinical spectrums of following diseases may overlap with chancroid:

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.

Comparison with syphilis

There are many differences and similarities between the conditions syphilitic chancre and chancroid.

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.[5]

Treatment

The CDC recommendation for chancroid is either a single oral dose (1 gram) of azithromycin, a single IM dose of 250 mg ceftriaxone, oral 500 mg of erythromycin q.i.d for seven days, or 500 mg of Ciprofloxacin b.i.d for three days.[6] Treatment may include more than one prescribed medication.

Abscesses are drained.

H. ducreyi is resistant to sulfonamides, tetracyclines, penicillins, chloramphenicol, ofloxacin, and trimethoprim.Recently, several erythromycin resistant isolates have been reported.[5]

Aminoglycosides such as Gentamicin, Streptomycin, and Kanamycin have been used to successfully treat Chancroid; however aminoglycoside-resistant strain of H. ducreyi have been observed in both laboratory and clinical settings.[7] 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.

Over the last two decades, no new treatment regime for Chancroid or H. ducreyi infection has been published. It is still assumed that the above described treatment regime is and will be effective against H. ducreyi infection.[6]

Complications

  • Extensive adenitis may develop.
  • Large inguinal abscesses may develop and rupture to form draining sinus or giant ulcer.
  • Superinfection by Fusarium and Bacteroides. These later require debridement and may result in disfiguring scars.
  • Phimosis can develop in long standing lesion by scarring and thickening of foreskin, which may subsequently require circumcision.

Prognosis

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

History

Chancroid has been known to humans since time of ancient Greeks.[8] Some of important events on historical timeline of chancre are:

YearEvent
1852Leon Bassereau distinguished chancroid from syphilis (i.e. soft chancre from hard chancre)
1890sAugusto Ducrey identified H. ducreyi
1900Benzacon and colleagues isolated H. ducreyi
1970sHammond and colleagues developed selective media

References

  1. James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. p. 274. ISBN 0-7216-2921-0.
  2. Rapini, Ronald P.; Bolognia, Jean L.; Jorizzo, Joseph L. (2007). Dermatology: 2-Volume Set. St. Louis: Mosby. ISBN 1-4160-2999-0.
  3. Medical Microbiology: The Big Picture. McGraw Hill Professional. p. 243. ISBN 9780071476614.
  4. "Error 404 - Page Not Found". pathmicro.med.sc.edu. Retrieved 19 April 2018.
  5. 1 2 3 4 CURRENT Diagnosis & Treatment of Sexually Transmitted Diseases. McGraw-Hill Companies, Inc. 2007. pp. 69–74. ISBN 9780071509619.
  6. 1 2 Lautenschlager, Stephan; Kemp, Michael; Christensen, Jens Jørgen; Mayans, Marti Vall; Moi, Harald (2017-01-12). "2017 European guideline for the management of chancroid". International Journal of STD & AIDS. 28 (4): 324–329. doi:10.1177/0956462416687913. ISSN 0956-4624.
  7. Morse, Stephen (1989). "Chancroid and Haemophilus ducreyi". www.europepmc.org. Retrieved 30 June 2018.
  8. Sexually Transmitted Diseases (4th ed.). McGraw Hill Professional. 2007. pp. 689–698. ISBN 9780071417488.
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