Penicillin and Preventing Recurrent Leg Infections | Action Medical Research | Children's Charity

A new challenge for penicillin: preventing recurrent leg infections

First published on 1 September 2005

Updated on 1 May 2013

What did the project achieve?

Penicillin can prevent repeat attacks of a common, painful and disabling skin infection called cellulitis, according to the results of this recently completed study.1,2

“We have discovered that low-dose penicillin treatment over one year almost halves your chances of suffering another bout of cellulitis of the leg if you have already experienced this infection at least twice,” explains Professor Hywel Williams.

Cellulitis begins as a red, painful and tender patch of skin. Some sufferers develop more serious symptoms, which can become life threatening within just a few days without treatment.

Professor Williams led a large group of researchers from 28 hospitals across the UK, recruiting 274 patients to this study. Half of the patients took low doses of penicillin; the others were given a placebo – or dummy – treatment. During the one-year treatment period, 22 per cent of people on penicillin found their cellulitis recurred, compared with 37 per cent on the dummy drug.

“We are publishing the results of our study – the largest such study to date – in the prestigious New England Journal of Medicine,” says Professor Williams. “The study now provides doctors and patients with clear information on the potential benefit of low dose penicillin to prevent recurrent cellulitis. This could have a big impact on the lives of millions of sufferers.”

This research was completed on 31 October 2011

Cellulitis is a common, painful and disabling infection that can strike the same patients time and time again. It accounts for around three percent of all hospital admissions. Although cellulitis responds to antibiotics, there's no solid proof that extended courses prevent it recurring. Could a low dose of penicillin be all that's needed?

What's the problem and who does it affect?

Patients face repeat infection

An extraordinary three percent of people admitted to hospital have an infection called cellulitis. They stay in hospital for around ten days. Despite an effective cure, more than 1 in 4 people get cellulitis again. Cellulitis begins as a red, painful and tender patch of skin, often on patients' legs. The skin becomes hot and swollen. Some people develop a fever and other more serious symptoms. Without treatment, infection can spread to the bloodstream, becoming life threatening within just a few days. Doctors lack information on preventing cellulitis Though doctors can treat cellulitis, they have no clear guidance on how to prevent it. As well as recurrences of cellulitis, many people suffer persistent complications, such as swelling of their leg or ulcers. Doctors lack funding to research cellulitis. They believe this might be because the disorder doesn't have a high enough profile and attempts to prevent cellulitis often involve a course of penicillin, which some see as old-fashioned. What's more, research is difficult to coordinate - patients are treated in several different hospital departments and few hospitals see enough patients to perform significant clinical trials independently.

What is the project trying to achieve?

Does penicillin stop cellulitis recurring?

Patients from 10 to 15 hospitals throughout the UK will take part in a clinical trial Patients leaving hospital after successful treatment for cellulitis of the leg will be split, randomly, into two groups - one group will take a low dose of penicillin for 12 months, the other will take an inactive placebo tablet. Neither patients nor their doctors will know who receives active treatment. Over the next three years, doctors will record any recurrences of cellulitis and any leg swelling or ulceration. They will follow patients' progress closely, by posting out questionnaires, telephoning patients periodically, and being readily available for emergency consultations. Patients will complete diaries. The results should show whether penicillin can stop cellulitis from recurring and prevent leg swelling and ulceration.

What are the researchers' credentials?

Project LeaderDr H Williams MSc, PhD, FRCP
Project team
  • Dr K Thomas PhD
  • Dr N Cox FRCP
  • Professor N J Reynolds MD, FRCP
  • Professor P Mortimer FRCP, MD
  • Professor A Nunn
  • Dr S Meredith MRCGP, MFPH
  • Dr D de Berker MBBS, MRCP
LocationCentre of Evidence Based Dermatalogy, University of Nottingham in conjunction with Dermatology Department at the Cumberland Infirmary and Cardiac and Vascular Sciences at St George's Hospital Medical School, London and Medical Research Council, London and Dermatological Sciences, University of Nottingham and Dermatology Department at Bristol Royal Infirmary
Other locations
  • Dermatology Department, Cumberland Infirmary, Carlisle
  • Dermatological Sciences, University of Newcastle
  • Cardiac and Vascular Sciences (Dermatology), St George's Hospital Medical School, London
  • Medical Research Council Clinical Trials Unit, London
  • Dermatology Department, Bristol Royal Infirmary.
DurationThree years
Grant awarded7 July 2005
Start date1 July 2006
End date31 October 2011
Grant amount£116,175.00
Grant codeSP4063

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The UK Dermatology Clinical Trials Network will coordinate the clinical trial from the co-ordinating centre at the University of Nottingham. This extensive network comprises 170 dermatologists and dermatology nurses. They will help to recruit patients quickly to the study and will spread news of the trial's results, so it will make an immediate impact on how patients are treated. The project leader, Professor Hywel Williams, and his colleague, Dr Kim Thomas, have both managed several clinical trials in recent years. Dr Neil Cox, the clinical lead for this project, has a long-standing interest in cellulitis. Professor Nick Reynolds has extensive experience of conducting randomised clinical trials. And Professor Mortimer is an international authority on lymphoedema - the leg swelling that is both a cause and complication of cellulitis.

Who stands to benefit from this research and how?

Pencillin: a simple solution

Penicillin is a relatively cheap and simple treatment that is tolerated well by most people. If it stops cellulitis from recurring, and prevents the associated leg swelling and ulceration, penicillin would have a major impact on both patients and the NHS. For patients, successfully preventing cellulitis would bring freedom from long-term suffering. Just one bout of cellulitis is bad enough - bringing pain, disability and a long stay in hospital. But at least one quarter of people go on to suffer from cellulitis again. Patients also face a long-term risk of getting persistent swelling or ulcers in their leg. Indeed, the problem can be cyclical, as the swelling can itself cause further episodes of cellulitis.

Saving money

Preventing cellulitis would also save the NHS a significant amount of money. With an average inpatient stay of ten days, each patient costs the NHS an estimated £1500 every time they become ill. Since three percent of hospital admissions are for cellulitis, costs to the NHS soon mount up.

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