INTRODUCTION
Patients with atopic dermatitis (AD) are known to have a
predisposition to colonization by microbial organisms,
including both Staphylococcus aureus and herpes simplex
virus (HSV).1 In fact, S aureus is considered a critical cofactor
in AD.2 In recent years, increased attention has been paid to
methicillin-resistant strains of S aureus, (MRSA), which is identified
in both hospital-acquired (HA) and community-acquired
(CA) strains. Community-acquired MRSA has been identified
in AD patients, but studies suggest a low incidence of MRSA
among AD patients.3,4 In one analysis, there was a significantly
lower rate of CA-MRSA among pediatric AD patients than in the
general pediatric population.4
Staphylococcus aureus infection leads to exacerbation of eczema
and may induce flares in atopic skin.5,6 Suspected mechanisms
for Staphylococcus-mediated inflammation include production
of inflammatory cytokines following either direct infection of
keratinocytes or immune cells or indirectly by bacterial byproducts.6 Antibacterial therapy aimed at reducing the bacterial load is
considered a standard approach to care for infected, flaring AD,
although antibiotic therapy in non-clinically infected individuals is
not recommended.7 Topical mupirocin is an established choice for
the management of infected AD, although it has been associated
with some degree of antibacterial resistance, leading to calls for
judicious use.8 Retapamulin 1% ointment is a relatively novel
topical antibiotic formulation that may be a suitable alternative for
the treatment of clinically infected AD.
Retapamulin 1% ointment is indicated for use in adults and
pediatric patients 9 months to 98 years of age for the topical
treatment of impetigo due to methicillin-susceptible S aureus or Streptococcus pyogenes. In vitro, retapamulin is highly potent
against S aureus and has a lower propensity to develop resistance
than mupirocin.9,10 Furthermore, clinical studies suggest the fiveday
BID dosing schedule is effective against impetigo due to
methicillin-susceptible S aureus and S pyogenes.
The first and only prescription topical antibacterial in the
pleuromutilin class, retapamulin confers its antibacterial
effects via its effects on 3 different aspects of microbial protein
synthesis. It prevents normal formation of the 50S ribosomal
subunit.11 Additionally, it is shown to block P-site interactions
and inhibit peptidyl transfer by bacterial cells.12
STUDY DESIGN
A single-center, open-label pilot study was conducted to
investigate the efficacy and safety of retapamulin 1% (Altabax,
