Short and Long Term Outcomes of Doxycycline Versus Trimethoprim-Sulfamethoxazole for Skin and Soft Tissue Infections Treatment

This is a phase IIb multicenter, randomized, double‐blind trial in which enrolled subjects with abscess or cellulitis will be treated with either DOXY or TMP‐SMX. The overall objective is to provide a clinically relevant treatment strategy for uSSTI in children and adults in areas where CA‐MRSA is prevalent. Out‐patient subjects, both children and adults with abscess and/or purulent cellulitis will be enrolled into a randomized, double‐blind trial in which enrolled subjects will be treated with either DOXY or TMP‐SMX. Background: Staphylococcus aureus is the most commonly identified cause of skin infections. In the last 15 years, there also has been an large increase in Staphylococcus aureus skin infection attributable to CA‐MRSA (Methicillin‐resistant Staphylococcus aureus) throughout the United States. However, optimal treatment remains unclear and several commonly used antibiotics such as doxycycline are commonly used but understudied. As resistance among CA‐MRSA strains to commonly used antibiotics such as clindamycin continues to increase, there is a need to understand the relative safety and efficacy of alternative treatments, such as doxycycline. This clinical trial will evaluate DOXY and TMP‐SMX for the outpatient management of uSSTI in two metropolitan areas, Los Angeles and St. Louis, cities with high prevalence of CA‐MRSA. This trial will test important unanswered hypotheses relating to the treatment of CA‐MRSA uSSTI and it will advance healthcare providers' ability to successfully manage adults and children with uSSTIs in areas where CA‐MRSA is prevalent. Methods: Out‐patient subjects, both children and adults with abscess and/or purulent cellulitis will be enrolled into a randomized, double‐blind trial in which enrolled subjects will be treated with either DOXY or TMP‐SMX. Using a 1:1 randomized controlled trial of 462 subjects, the investigators aim to 1) compare the cure rate of DOXY to that of TMP‐SMX for the treatment of patients throughout the study 2) compare rates of adverse events and of adverse events that are treatment limiting between DOXY and TMP‐SMX 3) estimate relapse and recurrence of uSSTI among patients treated with DOXY and of TMP‐SMX 4) estimate treatment failure among patients with uSSTI colonized with S. aureus at the anterior nares and oropharynx.