One of the most common diagnoses in primary care is cellulitis. Streptococcus sp. and Staphylococcus aureus are the most common etiologic organisms of cellulitis and usually respond to empiric antibiotics. A seven- to 10-day regimen is the recommended treatment. However, uncomplicated cellulitis has a strong inflammatory response with a low yield for bacteria in the affected area. Because shorter courses of antibiotics have been shown to treat other bacterial infections effectively, a shorter antibiotic regimen may be just as effective as a longer regimen in treating uncomplicated cellulitis. Hepburn and colleagues evaluated the effectiveness of a five-day versus a 10-day antibiotic course in treating uncomplicated cellulitis.

This randomized, double-blind, placebo-controlled study involved patients with presumed cellulitis who presented to an army medical center. Patients were excluded if they had preexisting conditions that would complicate the course of cellulitis, including bacteremia, severe sepsis, or deep soft tissue infection. All participants received five days of antibiotics, levofloxacin in most cases, orally or intravenously.

Researchers evaluated the severity of cellulitis at each office visit using a clinical scoring system, and the patients performed a self-assessment. On day 5, patients made a follow-up visit and were randomized to receive five more days of antibiotics or placebo. The patients made subsequent follow-up visits between days 10 and 14, and on day 28 patients were contacted by telephone. The primary outcome was resolution of infection at day 14 with no recurrence by day 28. Clinical failure in the short-course group was defined as worsening of signs and symptoms beyond five days of therapy, and antibiotic failure was defined as the need for further intervention (e.g., abscess drainage, restarting antibiotics) or recurrent infection.

A total of 87 patients participated in the study, with 44 patients assigned to short-course antibiotic therapy. Cellulitis was resolvedbyday14withnorecurrencebyday28 in 98 percent of patients in both the long- and short-course groups. The medications caused no serious adverse events. However, three patients discontinued levof loxacin therapy during the study, two because of gastrointestinal intolerance and one because of a rash. The clinical scores were similar between the two groups and decreased over time. The participants’ self-assessments also produced the same results in both groups.

The authors conclude that a five-day course of antibiotics can treat patients with uncomplicated cellulitis as effectively as a 10-day course. Improvement rates, measured objectively and subjectively, also were similar.