Retapamulin, a topical pleuromutilin antibiotic, is the first in a new class of topical antibiotics approved for human use. In the European Union (EU), retapamulin is approved for the treatment of impetigo and secondarily-infected traumatic lesions in persons nine or more months of age. This study is designed to examine retapamulin use in the pediatric population less than nine months of age. We will conduct a five-year assessment of prescriptions for retapamulin using the General Practice Research Database. For each year of reporting, the observed frequencies of prescriptions of retapamulin, with or without same-day co-prescriptions of topical mupirocin or fusidic acid, will be identified. The five-year reporting period will include five years of distinct, non-overlapping, non-cumulative prescription use of first exposure to retapamulin, with or without same-day co-prescription of topical mupirocin or fusidic acid.

Inclusion Criteria:

• The study population will consist of all registered "research standard" patients on GPRD, as evaluated annually for five years. For each year of observation, the denominator of persons will be patients registered for at least one month during the prior calendar year. Hence, the five-year reporting period for distinct, non-overlapping, non-cumulative prescription use and will categorize persons by date of birth (mm/dd/year).

Exclusion Criteria:

• Enrollment in GPRD of less than one month duration.

The GPRD contains detailed information for a sample of patients from representative general practices throughout the United Kingdom. Patient data included in the GPRD were drawn from the computer systems used by general practitioners to maintain the clinical records within their practices and contain all records deemed relevant to patient care. Prescriptions of Altabax, Altargo, Mupirocin and Fucidin will be captured.