Fusidic acid in skin and soft tissue infections.

Skin and soft skin tissue infections are usually caused by Staphylococcus aureus and Streptococcus pyogenes. In vitro data show good activity of fusidic acid against staphylococci but the minimal inhibitory concentrations for streptococci are relatively high indicating marginal activity. A limited number of clinical trials have been performed using oral fusidic acid and although all have methodological problems the difference in susceptibility of these two organisms is apparent. The end of study cure rates for these studies were 91-99% for S. aureus and 75-85% for S. pyogenes. Topical therapy has been used in a number of forms and for different skin infections. Comparative studies have been conducted with mupirocin, trimethoprim/polymixin cream, hydrogen peroxide and combination steroid preparations. For most of these studies fusidic acid was equivalent to the comparator agent except where there was a proven S. pyogenes infection. Studies with topical fusidic acid have also been reported in specific disease states such as acne, erythrasma, and abscesses with good results.