Case 7 – An 18-year-old woman with vaginal discharge and vulvar pain

An 18-year-old woman presents to the health clinic complaining of a fever and malaise. Upon further questioning she also admits to a foul vaginal discharge and vulvar pain. She denies having sexual intercourse recently, but she does admit to “blacking out” at a party 1 week ago and is worried that she may have unknowingly and unwillingly had unprotected sexual intercourse then. Her temperature is 38.6°C (101.5°F). There is significant tender lymphadenopathy in the inguinal region. Examination of the external genitalia reveals three painful, well-demarcated soft ulcers with necrotic bases in the vestibule of the vagina. Pelvic examination reveals a foul-smelling purulent discharge.

What is the most likely diagnosis?

Chancroid. Chancroid is a sexually transmitted infection caused by the gram-negative bacillus Haemophilus ducreyi. The infection is spread by direct sexual contact when the organism comes in contact with an open lesion; the organism cannot invade intact tissue.

How is the diagnosis made?

Chancroid is generally diagnosed clinically as it is difficult to isolate the causative organism, H. ducreyi. The best material for culturing and isolating the organism is aspirated pus from a bubo, but the organism can be isolated in less than a third of cases. Polymerase chain reaction of genital samples is becoming a more widely available form of testing. Importantly, syphilis should be ruled out before making the diagnosis of chancroid.

What other infections should be considered in a patient with genital ulcers?

Patients presenting with genital ulcers should be screened for other sexually transmitted infections such as chlamydia, gonorrhea, HIV, hepatitis B virus, and hepatitis C virus.
Genital ulcers are an important factor in the spread of HIV, as HIV-negative persons with genital ulcers have higher rates of acquisition, and HIV-positive persons with genital ulcers transmit HIV more effectively.

How do the genital lesions in this condition compare to those in other sexually transmitted diseases?

The best treatment option is one dose of azithromycin (1 g by mouth) or ceftriaxone (250 mg intramuscuarly). Ciprofloxacin (500 mg by mouth twice a day for 3 days) is another option, but less desirable give the multidose requirement.By Cynthia L. Bartus, MD, Resident in Dermatology, Emory University School of Medicine; in association with Le TT, Schabelman E, Shivaram A, and Klein J, eds: First Aid Cases for the USMLE Step 2 CK. New York: McGraw-Hill, 2007.