Prophylactic antibiotics for the prevention of cellulitis

Background: Cellulitis of the lower leg accounts for 2-3% of hospital admissions (Cox et al, 1998), with an average length of in-patient stay of nine days. Studies have reported that up to half of these patients suffer further episodes (Cox et al, 1998; Dupuy et al, 1999). Reducing the recurrence of cellulitis could therefore have a significant impact on both patient morbidity and NHS costs. Aims: To assess whether prophylactic antibiotics prescribed after an episode of cellulitis of the leg results in fewer subsequent attacks and reduced health service costs (PATCH prophylactic antibiotics for the treatment of cellulitis at home). Methods: This article describes two related studies in which participants are randomised to receive either 12 months of prophylaxis (PATCH I) or six months of prophylaxis (PATCH II). The PATCH I study recruits only patients with recurrent disease defined as two or more episodes of cellulitis in the last three years. PATCH II has more open criteria and includes patients with a first episode of cellulitis and also participants with recurrent disease. It is expected that 260 patients will be recruited into PATCH I and 400 patients into PATCH II.

Feasibility study to inform the design of a UK multi-centre randomised controlled trial of prophylactic antibiotics for the prevention of recurrent cellulitis of the leg

Background: This paper describes the results of a feasibility study for a randomised controlled trial (RCT). Methods: Twenty-nine members of the UK Dermatology Clinical Trials Network (UK DCTN) expressed an interest in recruiting for this study. Of these, 17 obtained full ethics and Research & Development (R&D) approval, and 15 successfully recruited patients into the study. A total of 70 participants with a diagnosis of cellulitis of the leg were enrolled over a 5-month period. These participants were largely recruited from medical admissions wards, although some were identified from dermatology, orthopaedic, geriatric and general surgery wards. Data were collected on patient demographics, clinical features and willingness to take part in a future RCT. Results: Despite being a relatively common condition, cellulitis patients were difficult to locate through our network of UK DCTN clinicians. This was largely because patients were rarely seen by dermatologists, and admissions were not co-ordinated centrally. In addition, the impact of the proposed exclusion criteria was high; only 26 (37%) of those enrolled in the study fulfilled all of the inclusion criteria for the subsequent RCT, and were willing to be randomised to treatment. Of the 70 participants identified during the study as having cellulitis of the leg (as confirmed by a dermatologist), only 59 (84%) had all 3 of the defining features of: i) erythema, ii) oedema, and iii) warmth with acute pain/tenderness upon examination. Twenty-two (32%) patients experienced a previous episode of cellulitis within the last 3 years. The median time to recurrence (estimated as the time since the most recent previous attack) was 205 days (95% CI 102 to 308). Service users were generally supportive of the trial, although several expressed concerns about taking antibiotics for lengthy periods, and felt that multiple morbidity/old age would limit entry into a 3-year study. Conclusion: This pilot study has been crucial in highlighting some key issues for the conduct of a future RCT. As a result of these findings, changes have been made to i) the planned recruitment strategy, ii) the proposed inclusion criteria and ii) the definition of cellulitis for use in the future trial.