Penicillin to prevent recurrent leg cellulitis

Kim S Thomas, Angela M Crook, Andrew J Nunn, Katharine A Foster, James M Mason, Joanne R Chalmers, Ibrahim S Nasr, Richard J Brindle, John English, Sarah K Meredith, Nicholas J Reynolds, David de Berker, Peter S Mortimer, Hywel C Williams, U.K. Dermatology Clinical Trials Network's PATCH I Trial Team, Anthony Ormerod

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121 Citations (Scopus)


Cellulitis of the leg is a common bacterial infection of the skin and underlying tissue.
We compared prophylactic low-dose penicillin with placebo for the prevention of
recurrent cellulitis.
We conducted a double-blind, randomized, controlled trial involving patients with
two or more episodes of cellulitis of the leg who were recruited in 28 hospitals in
the United Kingdom and Ireland. Randomization was performed according to a
computer-generated code, and study medications (penicillin [250 mg twice a day] or
placebo for 12 months) were dispensed by a central pharmacy. The primary outcome
was the time to a first recurrence. Participants were followed for up to 3 years.
Because the risk of recurrence was not constant over the 3-year period, the primary
hypothesis was tested during prophylaxis only.
A total of 274 patients were recruited. Baseline characteristics were similar in the
two groups. The median time to a first recurrence of cellulitis was 626 days in the
penicillin group and 532 days in the placebo group. During the prophylaxis phase,
30 of 136 participants in the penicillin group (22%) had a recurrence, as compared
with 51 of 138 participants in the placebo group (37%) (hazard ratio, 0.55; 95%
confidence interval [CI], 0.35 to 0.86; P=0.01), yielding a number needed to treat to
prevent one recurrent cellulitis episode of 5 (95% CI, 4 to 9). During the no-intervention
follow-up period, there was no difference between groups in the rate of a first recurrence (27% in both groups). Overall, participants in the penicillin group had fewer
repeat episodes than those in the placebo group (119 vs. 164, P=0.02 for trend).
There was no significant between-group difference in the number of participants
with adverse events (37 in the penicillin group and 48 in the placebo group, P=0.50).
In patients with recurrent cellulitis of the leg, penicillin was effective in preventing
subsequent attacks during prophylaxis, but the protective effect diminished progressively once drug therapy was stopped. (Funded by Action Medical Research;
PATCH I number, ISRCTN34716921.)
Original languageEnglish
Pages (from-to)1695-1703
Number of pages9
JournalThe New England Journal of Medicine
Issue number18
Publication statusPublished - 2 May 2013


  • Penicillins
  • Double-Blind Method
  • Humans
  • Aged
  • Recurrence
  • Health Care Costs
  • Leg
  • Anti-Bacterial Agents
  • Health Services
  • Cellulitis
  • Follow-Up Studies
  • Middle Aged
  • Female
  • Male


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