Chancroid in Dallas: new lessons from an old disease.

In June 1986, an unusual number of cases of darkfield negative, nonvesicular, painful genital ulcers were noted in men presenting to the Sexually Transmitted Diseases Clinic of the Dallas County Health Department. Serologic findings were routinely nonreactive in these patients. This clinical presentation was consistent with a diagnosis of chancroid, and empiric therapy with erythromycin proved quite efficacious. A retrospective review of charts revealed several similar presentations in May. After 3 weeks of experimentation with culture media, positive cultures for Haemophilus ducreyi were obtained and confirmed by the Centers for Disease Control, definitively establishing the presence of chancroid in Dallas. By year's end, 383 cases of chancroid had been diagnosed.