Short-term effects of topical fusidic acid or mupirocin on the prevalence of fusidic acid resistant (FusR) Staphylococcus aureus in atopic eczema.
BACKGROUND
Staphylococcus aureus has a role in the pathophysiology of atopic eczema. Topical fusidic acid is widely used in its treatment. There is concern that topical use of fusidic acid may be driving the selection and dissemination of fusidic acid-resistant (FusR) S. aureus.


OBJECTIVE
To test the hypothesis that treatment of atopic eczema for 2 weeks with topical fusidic acid/steroid combination can increase carriage of FusRS. aureus.


METHODS
Forty-six patients with atopic eczema were allocated randomly to one of two treatment groups. Group 1 (28 patients) were treated with topical 2% fusidic acid plus 0.1% betamethasone cream, and group 2 (18 patients) with topical 2% mupirocin and 0.1% betamethasone cream. The clinical response and nasal and skin colonization with S. aureus were recorded before treatment and after 1 and 2 weeks of therapy.


RESULTS
Baseline samples from the site of worst eczema showed S. aureus (sensitive and resistant) in 76% of patients, and FusRS. aureus in 26%, with no significant difference between treatment groups. After 1 and 2 weeks, both groups showed similar significant clinical improvement. The overall median clinical improvement was paralleled by a reduction in prevalence and population density of S. aureus (sensitive and resistant) at the worst eczema site (P < 0.0001). However, for FusRS. aureus there was no significant change in the prevalence of carriage, or population density in either group compared to baseline. Over 50% of patients carried S. aureus in the nerves and over 20% carried FusRS. aureus. Neither regimen affected either the prevalence or population density of S. aureus or FusRS. aureus in the nerves.


CONCLUSIONS
In this small study there is no evidence to support the hypothesis that short-term treatment of atopic eczema with fusidic acid/steroid combination increases fusidic acid resistant S. aureus during a 2-week period.
Ravenscroft
J C
JC
Department of Dermatology, Harrogate District Hospital, Lancaster Park Road, Harrogate HG2 7SX, UK. jcravenscroft@doctors.org.uk
Layton
A M
AM
Eady
E A
EA
Murtagh
M S
MS
Coates
P
P
Walker
M
M
Cove
J H
JH
D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D002353:Carrier State; D016009:Chi-Square Distribution; D002648:Child; D002675:Child, Preschool; D003876:Dermatitis, Atopic / Q000188:drug therapy* / Q000382:microbiology*; D004352:Drug Resistance, Microbial; D005260:Female; D005672:Fusidic Acid / Q000008:administration & dosage*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016712:Mupirocin / Q000008:administration & dosage*; D012737:Sex Factors; D013211:Staphylococcus aureus; D018709:Statistics, Nonparametric; D013997:Time Factors; D016896:Treatment Outcome
D000900:Anti-Bacterial Agents; D005672:Fusidic Acid; D016712:Mupirocin