Background Cellulitis (erysipelas) of the leg is a common, painful infection of the
skin and underlying tissue. Repeat episodes are frequent, cause significant morbidity
and result in high health service costs.
Objectives To assess whether prophylactic antibiotics prescribed after an episode of
cellulitis of the leg can prevent further episodes.
Methods Double-blind, randomized controlled trial including patients recently treated
for an episode of leg cellulitis. Recruitment took place in 20 hospitals. Randomization
was by computer-generated code, and treatments allocated by post
from a central pharmacy. Participants were enrolled for a maximum of 3 years
and received their randomized treatment for the first 6 months of this period.
Results Participants (n = 123) were randomized (31% of target due to slow
recruitment). The majority (79%) had suffered one episode of cellulitis on entry
into the study. The primary outcome of time to recurrence of cellulitis included
all randomized participants and was blinded to treatment allocation. The hazard
ratio (HR) showed that treatment with penicillin reduced the risk of recurrence
by 47% [HR 0Æ53, 95% confidence interval (CI) 0Æ26–1Æ07, P = 0Æ08]. In the
penicillin V group 12 ⁄60 (20%) had a repeat episode compared with 21 ⁄63
(33%) in the placebo group. This equates to a number needed to treat (NNT) of
eight participants in order to prevent one repeat episode of cellulitis [95% CI
NNT(harm) 48 to ¥ to NNT(benefit) 3]. We found no difference between the
two groups in the number of participants with oedema, ulceration or related
adverse events.
Conclusions Although this trial was limited by slow recruitment, and the result
failed to achieve statistical significance, it provides the best e available to
date for the prevention of recurrence of this debilitating condition.