Impetigo is the most common skin infection in childhood. Although oral antibiotic therapy has been the conventional treatment for several years, bacterial resistance has led to an increased use of topical therapy. Topical mupirocin is as effective as oral antibiotic therapy but also offers improved compliance and a lower risk of systemic side effects. Some researchers have advocated that mild cases of impetigo be treated with disinfectant alone, avoiding the use of antibiotics entirely. A meta-analysis of children with impetigo cons. cluded that treatment with fusidic acid cream provided results comparable to those of mupirocin therapy. Koning and colleagues evaluated the use of fusidic acid or placebo in a large study of Dutch children with impetigo.

General practitioners in Rotterdam, Netherlands, identified children 12 years and younger who had superficial, nonbullous impetigo covering less than 5 percent of their skin surface. Children with significant medical illnesses, those who had recently taken antibiotics, and those with contraindications to the study agents were excluded. The children were visited at home by a research nurse on the day of referral. After swabbing and assessing the lesions and collecting data, the nurse randomly assigned each patient to treatment with 2 percent fusidic acid cream or identical placebo three times daily. All patients were instructed to clean the lesions with povidoneiodine shampoo twice daily and to institute common hygienic measures. Treatment continued for 14 days or until the lesions disappeared. The research nurse visited each patient on days 7, 14, and 28 to collect data, swab lesions, and monitor compliance and side effects. Outcomes measured included clinical change and bacterial cure.

The average age of the children was five years, and both genders were equally represented. About 75 percent of lesions were on the head, and Staphylococcus aureus was isolated in about 75 percent of cases. After one week of treatment, 55 percent of the 76 children treated with fusidic acid cream and 13 percent of the 80 children using placebo were clinically cured. At the two-week follow-up, the corresponding rates were 73 and 60 percent, and by four weeks the rates were 92 and 88 percent. The differences between treatment and placebo were not significant at the two- and four-week follow-ups. Bacterial cure was achieved in one week in 91 percent of the children treated with fusidic acid compared with 32 percent of children treated with placebo. Side effects were reported in seven patients in the treated group and in 19 patients in the placebo group. The pain, burning, and redness reported were associated with the use of povidone-iodine shampoo.

The authors conclude that fusidic acid is a safe and effective first-line therapy for impetigo, providing rapid clinical and bacteriologic resolution. The traditional disinfectant regimen of povidone-iodine shampoo was associated with side effects, and its value in impetigo therapy is questionable.

editor's note: Although mild to moderate impetigo is often a self-limiting condition, social embarrassment and exclusion from school often prompt parents to seek urgent effective therapy. This results in widespread use of oral antibiotics for impetigo, raising concerns about possible side effects and bacterial resistance. This study validates the use of topical fusidic acid. Correlation with the earlier studies implies that the efficacy of fusidic acid is equivalent to that of topical mupirocin, which is, in turn, equivalent to oral antibiotics. Our challenge is to persuade parents that the simple topical treatments are as effective as antibiotics in milder cases of impetigo. Yet simple, traditional therapies are not always best. The side effects of povidone-iodine shampoo are noteworthy.—a.d.w.