Chancroid: Understanding This Painful STI

Chancroid is a sexually transmitted infection caused by bacteria Haemophilus ducreyi, which results in very painful genital sores. It is uncommon to find chancroid in developed countries, but not impossible.

The bacteria cause small blisters that pop and result in small sores that can spread and enlarge, joining forces with other sores to become one big sore.¹

The sores can get quite deep, impacting on other nearby tissue. Symptoms usually start three to seven days after infection, and the groin lymph nodes can become abscesses.

Symptoms of chancroid²

Small, bumps or pimples on genitals or around the anus that develop into ulcers
Possibly hard, tender, enlarged lymph nodes in the groin with red, shiny skin over the top
These lymph nodes may break down and pus can emerge

Diagnosis of chancroid

There is no test for chancroid available, so it can be a ‘diagnosis by exclusion’, by testing for other STIs. Chancroid is usually only diagnosed by a doctor and by taking samples of the pus to culture, despite culturing being difficult (they are hard to grow). Genital sores with no known (or obvious) cause may be suspected. Read more about non-STI genital ulcers here. ³

Treatments for chancroid

Even if the cause is unknown, an antibiotic is likely to be prescribed, with ceftriaxone (single intramuscular injection), azithromycin (single oral dose), ciprofloxacin (orally for three days), erythromycin (orally for one week). ^4,5

The buboes (abscesses) may need to be drained using an incision, while using antibiotics.⁶

References

1.
Bong CTH, Bauer ME, Spinola SM. Haemophilus ducreyi: clinical features, epidemiology, and prospects for disease control. Microbes and Infection. Published online September 2002:1141-1148. doi:10.1016/s1286-4579(02)01639-8
2.
Mohammed TT, Olumide YM. Chancroid and human immunodeficiency virus infection – a review. Int J Dermatology. Published online December 17, 2007:1-8. doi:10.1111/j.1365-4632.2007.03435.x
3.
Lewis DA. Chancroid: clinical manifestations, diagnosis, and management. Sexually Transmitted Infections. Published online February 1, 2003:68-71. doi:10.1136/sti.79.1.68
4.
B. Junior W, Di Chiacchio NG, Di Chiacchio N, Romiti R, Criado PR, Velho PENF. A comparative study of single-dose treatment of chancroid using thiamphenicol versus Azithromycin. Braz J Infect Dis. Published online June 2009:218-220. doi:10.1590/s1413-86702009000300012
5.
Martin DH, Sargent SJ, Wendel GD, McCormack WM, Spier NA, Johnson RB. Comparison of Azithromycin and Ceftriaxone for the Treatment of Chancroid. Clinical Infectious Diseases. Published online August 1, 1995:409-414. doi:10.1093/clinids/21.2.409
6.
ERNST AA, MARVEZ-VALLS FE, MARTIN DH. Incision and Drainage Versus Aspiration of Fluctuant Buboes in the Emergency Department During an Epidemic of Chancroid. Sexually Transmitted Diseases. Published online July 1995:217-220. doi:10.1097/00007435-199507000-00003