Double-blind study comparing erythromycin and mupirocin for treatment of impetigo in children: implications of a high prevalence of erythromycin-resistant Staphylococcus aureus strains

Abstract

Staphylococcus aureus has been consistently isolated from a high proportion of impetiginous lesions, and in several recent studies, it was present in the majority of the cases. Since recently a large proportion of S. aureus strains in our community showed erythromycin resistance, we undertook a prospective double-blind controlled study comparing topical mupirocin with oral erythromycin to determine (i) the prevalence of erythromycinresistant S. aureus strains in impetigo and (ii) whether an increased rate of failure of erythromycin treatment was associated with such resistance. A total of 102 patients 3 to 185 months old (median = 49 months) were enrolled. Culture was positive for 97 of 102 (95%) patients, and S. aureus was present in 93% of the patients for whom cultures were positive. S. aureus was the single pathogen in 64% of these patients. Erythromycinresistant S. aureus strains were present in 27 of 91 (28%) patients for whom cultures were positive. In all cases but one, S. aureus was resistant to penicillin, and in all cases it was sensitive to mupirocin. A marked difference was observed in favor of mupirocin in the clinical courses of the disease. However, only patients with erythromycin-resistant S. aureus strains had unfavorable courses compared with those treated with mupirocin (failure rate, 47 versus 2%, respectively). Patients with erythromycin-susceptible S. aureus strains who received erythromycin had a failure rate of 8%. In four patients, S. aureus strains initially susceptible to erythromycin became resistant during treatment. We conclude that erythromycin-resistant S. aureus strains are commonly isolated from impetigo in our region. In view of the increasing resistance of S. aureus to various antibiotic drugs, new therapeutic regimens should be sought for this common skin infection. In our setting, mupirocin seems an appropriate alternative.

Efficacy of a New Cream Formulation of Mupirocin: Comparison with Oral and Topical Agents in Experimental Skin Infections

“…The use of erythromycin in some geographical areas may be restricted, however, due to the high incidence of erythromycin-resistant S. aureus and rapidly increasing incidence of macrolide-resistant S. pyogenes in the etiology of impetigo (13,33). Additional factors limiting the use of erythromycin and other oral agents are gastrointestinal side effects (32; Hebert et al, 32nd ICAAC) and the frequency of administration, both of which may lead to reduced compliance.…”

Superficial community‐acquired skin infections: prevalence of bacteria and antibiotic susceptibility in France

“…The prevalence of haemolytic streptococci infection was much lower than in older studies. [10][11][12] The present study also measured the susceptibility to antibiotics currently used in the treatment of bacterial cutaneous infections and showed the stability of resistance rates. The level of susceptibility to mupirocin remained unchanged for S. aureus, because MICs remained £ 0.5 mg/L for all strains.…”

“…Antibiotic testing was performed as recommended by the French Society of Microbiology. 10 At the end of the study, all frozen strains were sent to the microbiology laboratory at Pitié-Salpétrière Hospital in Paris to determine the minimum inhibitory concentration (MIC) of pristinamycin, mupirocin and fusidic acid for Gram-positive cocci, a fluoroquinolone against Gram-negative rods, and methicillin against staphylococci.…”

Current concepts in the management of bacterial skin infections in children

“…[26] Topical mupirocin has been proved to be as effective as oral erythromycin in uncomplicated impetigo in children. [38] Efficacy of mupirocin is impaired in the presence of serum and also in weeping lesions because of high protein binding. [39] In many European countries, monotherapy with topical fusidic acid is not preferred currently, in view of the widespread resistance shown by both MSSA and MRSA; and combination of this topical agent with systemic oxazolidinones has been suggested.…”