STD Toolkit



  • Acute, painful, single or multiple non-indurated necrotizing ulcers
  • May or may not have inguinal lymphadenopathy

Definitive Diagnosis:

​Identification of Haemophilus ducreyi on special culture media.

​*Due to testing difficulty, a probable diagnosis for treatment may be made if the patient: has painful genital ulcers consistent with chancroid, tender suppurative lymphadenopathy, a negative syphilis test (no evidence of T. pallidum on darkfield exam or nonreactive RPR seven days after ulcer onset), and a negative herpes culture.

As chancroid is not common in the USA (7 cases total in 2016) routine testing is not recommended. Testing should only be done if the infection is suspected.

  • Culture - specimen is aspirate from lesion or lymph node. Not commercially available. Sensitivity is less than 80%.
Recommended, with reservations:
  • PCR - specimen is aspirate from lesion or lymph node. Check with lab for availability (no FDA approved tests - lab has to develop the test and do CLIA study)
Not Recommended:
  • Gram stain

First Line Treatment

Ceftriaxone (Rocephin) 250 mg IM in a single dose
Azithromycin 1 gm orally in a single dose

Alternative Treatment


Erythromycin base 500mg orally three times daily for 7 days
Ciprofloxacin 500mg orally twice daily for 3 days

HIV patients usually require a longer course of therapy. These patients should be referred to their personal physician.

Persons should be re-examined 3-7 days after initiation of therapy. If treatment is successful ulcers improve within 3 days. Time required for complete healing depends on the size of the ulcer. If no clinical improvement is evident the clinician must consider whether:

  • The diagnosis is correct
  • Co-infection with another STD exists
  • The person is infected with HIV
  • Noncompliance with treatment was possible
  • The H. ducreyi strain is resistant to the antimicrobial prescribed

Syphilis and HIV serology should be repeated in 2-3 months.

For more information on Chancroid, please see the CDC's Sexually Transmitted Diseases Treatment Guidelines, 2015.