Clinical and microbiological evaluation of 46 episodes of genital ulceration.

In 44 consecutive patients 46 episodes of genital ulceration were studied. The presumptive clinical diagnosis was evaluated by extensive microbiological investigations. In 15 (33%) episodes the clinical diagnosis did not accord with the microbiological one. Chancroidal lesions were most commonly found to have other microbiological aetiology. Secondary invasion of treponemal or viral lesions by other bacterial species (mostly anaerobes or pyogenic cocci) or genital pyodermia were the cause of confusion in six of nine cases of chancroid. In the other three a ducreyilike bacterium was found. Direct Gram staining of ulcer material did not help the diagnosis of chancroid. The implications of the results of this study for clinical practice are discussed.