Genital Ulcer Disease

Many studies have tried to describe a "typical" clinical picture for the different etiological diagnoses of genital ulcer disease (GUD) but have failed. Descriptions, such as regular shape, smooth base, undermined edge, friability, tenderness and purulence, are not sufficiently discriminatory (even for experienced clinicians) to make an etiological diagnosis in most cases. In a study in South Africa of 210 patients with genital ulcers, clinical diagnosis was compared with a gold standard laboratory test. Clinical diagnosis had a positive predictive value of 89 percent for chancroid, 47 percent for syphilis, and 19 percent for genital herpes.¹³ Dual infections were common, making an etiological diagnosis even more difficult. Without sophisticated laboratory tests, an etiological diagnosis of GUD is impossible.

The relative frequencies of the different causes of GUD vary between geographical areas but can also vary in time. For example, two studies on the etiologies of GUD, in Rwanda in 1986 and 1992, found there was a shift in the relative frequencies of different etiologies. As the prevalence of HIV infection increased, herpes became more important as an etiology of GUD.²²

In many developing countries, the etiologies of GUD most frequently found are syphilis and chancroid. Both are treated with simple antibiotics (erythromycin and benzathine penicillin, respectively).

An antiviral therapy for herpes is not available in most primary health care settings in developing worlds. It is important to treat for chancroid and syphilis, even if some of the genital ulcers treated are actually caused by herpes.

In Rwanda, three different approaches were compared for the management of syphilis and/or chancroid. The syndromic approach adopted by most developing countries, illustrated in Figure 7, resulted in 99 percent of the patients with syphilis and/or chancroid correctly managed. For the approach based on the result of a Rapid Plasma Reagin (RPR) test (if RPR positive, treat for syphilis; if RPR negative, treat for chancroid) and for a clinical etiological approach, the proportions of correctly managed patients were 82 percent and 38 percent, respectively.

Figure - Example of a Flowchart for the Management of Genital Ulcers - BRAZIL

Including an RPR test in a hierarchic model is not an improvement in genital ulcer case management because many chancroid cases are missed. However, based on the Rwanda data, including an RPR test in a syndromic approach (treating all RPR positive patients for both syphilis and chancroid, and all RPR negative patients for chancroid alone), leads to a reduction in unnecessary syphilis treatment of patients and their partners.