A comparative study of spectinomycin and erythromycin in the treatment of chancroid.

In a randomized, controlled study, 55 patients with genital ulcerations, culture-positive for Haemophilus ducreyi, were treated with a single intramuscular injection of 2 g spectinomycin. A further 61 patients were treated with a five-day oral course of erythromycin base (500 mg, three times daily). Treatment failure occurred in seven patients who received spectinomycin (13%), whilst no treatment failures were recorded among patients who received erythromycin. This difference in efficacy was statistically significant. In contrast, spectinomycin proved significantly more effective than erythromycin in the treatment of the lymphadenopathy associated with primary chancroid lesions.