Methods: This study will be a prospective study conducted in two tertiary care EDs. Patients will be excluded if they have been treated with antibiotics for the current bout of cellulitis prior to presenting to the ED, patients admitted to hospital and those patients with abscesses only. Hired research assistants (RAs) will administer a questionnaire at the initial ED visit with telephone follow-up 2 weeks later. Treatment failure will be defined as patients requiring subsequent hospitalization, initiation of intravenous antibiotics (if oral antibiotics were prescribed initially), or a change of oral antibiotics for the original cellulitis.