Low-dose penicillin for recurrent cellulitis?

The incidence of cellulitis is 24.6 in 1000 person-years, according to a US population-based study of insurance claims for the years 1997 to 2002—the most recent data available. The lower extremities are most commonly affected, accounting for 70% to 80% of cases. Risk factors associated with recurrence include venous insufficiency, lymphedema, overweight, skin breakdown, and leg edema, which are often difficult to modify. Keeping well hydrated to avoid skin breakdown, elevating affected extremities to decrease edema, wearing compression stockings, and treating tinea pedis can help reduce the incidence of recurrent cellulitis. Prophylactic antibiotics can help, as well. Which drug? What dose and duration? These questions aren’t easily answered, as recommendations vary among specialty groups. The Infectious Diseases Society of America recommends benzathine penicillin (1.2 million units/month IM), erythromycin 250 mg PO BID, penicillin V 1 g PO BID, or nasal mupirocin BID for 5 days per month for “frequent” cellulitis, but “frequent” is not clearly defined. The British Lymphology Society (BLS)’s first-line recommendation for patients with ≥2 episodes of cellulitis per year is penicillin V 250 mg BID (or penicillin V 500 mg BID for patients with a BMI ≥33) for one year, then penicillin V 250 mg daily for an additional year. The BLS suggests lifelong antibiotic prophylaxis if cellulitis recurs after 2 years of prophylaxis. Consensus is lacking as to the optimal duration of prophylactic antibiotics. Kremer et al found that prophylactic erythromycin for 18 months reduced recurrent cellulitis; Thomas et al showed an insignificant reduction in cellulitis recurrence with 6 months of low-dose penicillin in patients who’d had one prior episode. The study detailed in this PURL provides additional evidence about the use of prophylactic antibiotics for recurrent lower extremity cellulitis and tests the efficacy of a particular dose and duration.