Diagnosis A diagnosis based on history and physical examination alone is often inaccurate. Therefore, all women with genital ulcers should undergo a serologic test for syphilis (50). Because of the consequences of inappropriate therapy, such as tertiary disease and congenital syphilis in pregnant women, diagnostic efforts are directed at excluding syphilis. Optimally, the evaluation of a patient with a genital ulcer should include dark-field examination or direct immunoﬂuorescence testing for Treponema pallidum, culture or antigen testing for HSV, and culture for Haemophilus ducreyi. Dark-field or ﬂuorescent microscopes and selective media to culture for H. ducreyi often are not available in most offices and clinics. Even after complete testing, the diagnosis remains unconfirmed in one-fourth of patients with genital ulcers. For this reason, most clinicians base their initial diagnosis and treatment recommendations on their clinical impression of the appearance of the genital ulcer (Fig. 18.2) and knowledge of the most likely cause in their patient population (48).
Several clinical presentations are highly suggestive of specific diagnoses: 1.
A painless and minimally tender ulcer, not accompanied by inguinal lymphadenopathy, is likely to be syphilis, especially if the ulcer is indurated. A nontreponemal rapid plasma reagin (RPR) test, or venereal disease research laboratory (VDRL) test, and a confirmatory treponemal test—ﬂuorescent treponemal antibody absorption (FTA ABS) or microhemagglutinin–T. pallidum (MHA TP)—should be used to diagnose syphilis presumptively. Some laboratories screen samples with treponemal enzyme immunoassay (EIA) tests, the results of which should be confirmed with nontreponemal tests. The results of nontreponemal tests usually correlate with disease activity and should be reported quantitatively.
2.
Grouped vesicles mixed with small ulcers, particularly with a history of such lesions, are almost always pathognomonic of genital herpes. Nevertheless, laboratory confirmation of the findings is recommended because the diagnosis of genital herpes is traumatic for many women, alters their self-image, and affects their perceived ability to enter new sexual relationships and bear children. A culture test is the most sensitive and specific test; sensitivity approaches 100% in the vesicle stage and 89% in the pustular stage and drops to as low as 33% in patients with ulcers. Nonculture tests are about 80% as sensitive as culture tests. Because false-negative results are common with HSV cultures, especially in patients with recurrent infections, type-specific glycoprotein G-based antibody assays are useful in confirming a clinical diagnosis of genital herpes.
3.
One to three extremely painful ulcers, accompanied by tender inguinal lymphadenopathy, are unlikely to be anything except chancroid. This is especially true if the adenopathy is ﬂuctuant.
4.
An inguinal bubo accompanied by one or several ulcers is most likely chancroid. If no ulcer is present, the most likely diagnosis is LGV.
Recommended regimens for the treatment of chancroid include azithromycin, 1 g orally in a single dose; ceftriaxone, 250 mg intramuscularly in a single dose; ciproﬂoxacin, 500 mg orally twice a day for 3 days; or erythromycin base, 500 mg orally four times daily for 7 days. Patients should be reexamined 3 to 7 days after initiation of therapy to ensure the gradual resolution of the genital ulcer, which can be expected to heal within 2 weeks unless it is unusually large.