This article looks at the symptoms and causes of chancroid, including how it differs from syphilis. It also explains how chancroid is diagnosed and treated and what you can do to protect yourself and others from infection.
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Chancroid Symptoms
Chancroid is often mistaken for syphilis in the early stages. It usually starts as a red bump on the genitals or rectum that quickly turns into a pus-filled blister, usually within four to 10 days of exposure. The blister will typically rupture and form a deep ulcer with well-defined borders.
Unlike syphilis, the ulcers usually grow to a larger size—some as large as two inches—and can be extremely painful. By contrast, syphilis ulcers, calledchancres, are usually painless. The base on a chancroid ulcer can bleed easily if scratched or rubbed.
Chancroid can also cause swelling, tenderness, and inflammation of thelymph nodes in the groin. In fact, the swelling can sometimes be so severe that the lymph node rupture, causing a drainingabscess. This is also not a symptom associated with syphilis.
Males with chancroid generally get one ulcer, while females can get many. Females may also experiencedysuria(pain with urination), while males usually won’t.
Untreated chancroid ulcers can persist for up to three months and cause significant scarring.
ChancroidSores usually develop within 10 days of exposure.Ulcers may grow as large as two inches.Ulcers are very painful.Around 50% people will experience swollen lymph nodes in the groin.SyphilisSores usually develop within 21 days of exposure.Ulcers are typically smaller than an inch.Ulcers are typically painless.Swollen lymph nodes are not common.
ChancroidSores usually develop within 10 days of exposure.Ulcers may grow as large as two inches.Ulcers are very painful.Around 50% people will experience swollen lymph nodes in the groin.
Sores usually develop within 10 days of exposure.
Ulcers may grow as large as two inches.
Ulcers are very painful.
Around 50% people will experience swollen lymph nodes in the groin.
SyphilisSores usually develop within 21 days of exposure.Ulcers are typically smaller than an inch.Ulcers are typically painless.Swollen lymph nodes are not common.
Sores usually develop within 21 days of exposure.
Ulcers are typically smaller than an inch.
Ulcers are typically painless.
Swollen lymph nodes are not common.
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Cause
The bacteria can also pass through tiny breaks in the skin, called microabrasions, that occur during sexual intercourse.
Chancroid is relatively rare in the United States, although sporadic local outbreaks have been known to occur. Worldwide, chancroid is the most common cause of genital ulcer disease, particularly in resource-poor parts of Africa and the Caribbean.
Chancroid in the United StatesIn 2019, there were only eight reported cases of chancroid in the United States.
Chancroid in the United States
In 2019, there were only eight reported cases of chancroid in the United States.
Diagnosis
No laboratory test is able to immediately confirm the diagnosis of chancroid.There are also no FDA-cleared tests available to accurately detectHaemophilus ducreyi.
Although special tests are available toculture(grow)Haemophilus ducreyiin the lab (using a swab of fluid from a sore), they are difficult to source and are less than 80% accurate. Some labs in the United States have developed their own tests, callednucleic acid amplification tests (NAATs), to help diagnose chancroid.
But, for the most part, chancroid is diagnosed based on the features of the disease and the exclusion of other diseases that cause genital ulcers, such asdonovanosis.
Criteria for the Probable Diagnosis of ChancroidAccording to the Centers for Disease Control and Prevention (CDC), a probable diagnosis of chancroid can be made if the following four criteria are met:The person has one or more genital ulcers.The ulcers and swelling of lymph nodes are consistent with chancroid.There is no evidence of syphilis based on lab tests.There is no lab evidence ofgenital herpes, a far more common genital ulcer disease in the United States.
Criteria for the Probable Diagnosis of Chancroid
According to the Centers for Disease Control and Prevention (CDC), a probable diagnosis of chancroid can be made if the following four criteria are met:The person has one or more genital ulcers.The ulcers and swelling of lymph nodes are consistent with chancroid.There is no evidence of syphilis based on lab tests.There is no lab evidence ofgenital herpes, a far more common genital ulcer disease in the United States.
According to the Centers for Disease Control and Prevention (CDC), a probable diagnosis of chancroid can be made if the following four criteria are met:
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Treatment
For reasons not entirely clear, uncircumcised males and people with HIV are sometimes less responsive to treatment and may need to be re-treated. For this reason, follow-up testing should be performed three to seven days after completing therapy. For most people, symptoms will start to improve within that time frame.
Anyone suspected of having chancroid should also betested for HIV.
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Prevention
Chancroid is prevented in the same way as many other STIs, with barrier protection and other safer sex practices. Short of abstinence, this includes:
You should also notify sexual partners immediately if you have been diagnosed with chancroid. Sexual partners will likely be treated as a precaution.
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Summary
A Word From Verywell
Because chancroid closely resembles syphilis, it is important to give your health provider your complete medical and sexual history so they can reach the correct diagnosis. This includes advising the provider if you’ve had sex with a recent immigrant or visitor from parts of the world where chancroid is widespread.
The differentiation is especially important because chancroid and syphilis are treated differently. What works for syphilis will likely not work for chancroid, and vice versa.
6 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gonzalez-Beira C, Marks M, Chen CY, Roberts S, Mitja O.Epidemiology ofHaemophilus ducreyiinfections.Emerg Infect Dis.2016;22(1):1-8.Lautenschlager S, Kemp M, Christensen JJ, Mayans MV, Moi H.2017 European guideline for the management of chancroid.Int J STD AIDS. 2017;28(4):324-9. doi:10.1177/0956462416687913Roett MA.Genital ulcers: differential diagnosis and management.Am Fam Physician. 2020;101(6):355-361.Centers for Disease Control and Prevention.Chancroid.Koralur M, Chen CY, Pillay A, et al.Evaluation of a laboratory developed multiplex real-time PCR assay for diagnosis of syphilis, herpes, and chancroid genital ulcers in four public health laboratories in the United States.Sexually transmitted infections. 2021;98(6):448. doi:10.1136/sextrans-2021-055081Phiri S, Zadrozny S, Weiss HA, et al.Etiology of genital ulcer disease and association with HIV infection in Malawi.Sex Transm Dis. 2013;40(12):923-928. doi:10.1097/OLQ.0000000000000051Additional ReadingCenters for Disease Control and Prevention.Sexually transmitted infections treatment guidelines.
6 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Gonzalez-Beira C, Marks M, Chen CY, Roberts S, Mitja O.Epidemiology ofHaemophilus ducreyiinfections.Emerg Infect Dis.2016;22(1):1-8.Lautenschlager S, Kemp M, Christensen JJ, Mayans MV, Moi H.2017 European guideline for the management of chancroid.Int J STD AIDS. 2017;28(4):324-9. doi:10.1177/0956462416687913Roett MA.Genital ulcers: differential diagnosis and management.Am Fam Physician. 2020;101(6):355-361.Centers for Disease Control and Prevention.Chancroid.Koralur M, Chen CY, Pillay A, et al.Evaluation of a laboratory developed multiplex real-time PCR assay for diagnosis of syphilis, herpes, and chancroid genital ulcers in four public health laboratories in the United States.Sexually transmitted infections. 2021;98(6):448. doi:10.1136/sextrans-2021-055081Phiri S, Zadrozny S, Weiss HA, et al.Etiology of genital ulcer disease and association with HIV infection in Malawi.Sex Transm Dis. 2013;40(12):923-928. doi:10.1097/OLQ.0000000000000051Additional ReadingCenters for Disease Control and Prevention.Sexually transmitted infections treatment guidelines.
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Gonzalez-Beira C, Marks M, Chen CY, Roberts S, Mitja O.Epidemiology ofHaemophilus ducreyiinfections.Emerg Infect Dis.2016;22(1):1-8.Lautenschlager S, Kemp M, Christensen JJ, Mayans MV, Moi H.2017 European guideline for the management of chancroid.Int J STD AIDS. 2017;28(4):324-9. doi:10.1177/0956462416687913Roett MA.Genital ulcers: differential diagnosis and management.Am Fam Physician. 2020;101(6):355-361.Centers for Disease Control and Prevention.Chancroid.Koralur M, Chen CY, Pillay A, et al.Evaluation of a laboratory developed multiplex real-time PCR assay for diagnosis of syphilis, herpes, and chancroid genital ulcers in four public health laboratories in the United States.Sexually transmitted infections. 2021;98(6):448. doi:10.1136/sextrans-2021-055081Phiri S, Zadrozny S, Weiss HA, et al.Etiology of genital ulcer disease and association with HIV infection in Malawi.Sex Transm Dis. 2013;40(12):923-928. doi:10.1097/OLQ.0000000000000051
Gonzalez-Beira C, Marks M, Chen CY, Roberts S, Mitja O.Epidemiology ofHaemophilus ducreyiinfections.Emerg Infect Dis.2016;22(1):1-8.
Lautenschlager S, Kemp M, Christensen JJ, Mayans MV, Moi H.2017 European guideline for the management of chancroid.Int J STD AIDS. 2017;28(4):324-9. doi:10.1177/0956462416687913
Roett MA.Genital ulcers: differential diagnosis and management.Am Fam Physician. 2020;101(6):355-361.
Centers for Disease Control and Prevention.Chancroid.
Koralur M, Chen CY, Pillay A, et al.Evaluation of a laboratory developed multiplex real-time PCR assay for diagnosis of syphilis, herpes, and chancroid genital ulcers in four public health laboratories in the United States.Sexually transmitted infections. 2021;98(6):448. doi:10.1136/sextrans-2021-055081
Phiri S, Zadrozny S, Weiss HA, et al.Etiology of genital ulcer disease and association with HIV infection in Malawi.Sex Transm Dis. 2013;40(12):923-928. doi:10.1097/OLQ.0000000000000051
Centers for Disease Control and Prevention.Sexually transmitted infections treatment guidelines.
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