The Personalised Antibiotic Duration for Cellulitis (PAD-C) Study

Overview

Cellulitis is an increasingly common and unpleasant bacterial infection of the skin, usually affecting the legs. Patients experience pain and swelling, loss of mobility, fever, and chills. Patients may be left with chronic skin damage and 1 in 5 experience recurrences. Cellulitis is treated with antibiotics, but it is unclear as to how long treatment should be for. As a result, many patients get much longer antibiotic treatment than needed. This exposes patients to the risks of taking unnecessary antibiotics. This study aims to find out what features of individual patients predict a good, sustained recovery from cellulitis. These may include medical conditions and clinical response to the first few days of antibiotic treatment, such as changes in skin temperature. Patients who are being treated in hospital for cellulitis will be invited to take part. Information will be collected about patients who will be followed up for 3-6 months. Devices for measuring skin temperature will also be compared to see which one works best. This information will be used to help develop a set of rules that doctors can use to guide the length of antibiotic treatment. This should ensure that future patients receive the amount of antibiotics needed and no more.

This study is a single centre prospective cohort study of patients with cellulitis of the lower limb. The primary objective of this study is to understand what features of individual patients predict a sustained recovery from cellulitis. This information will be used to test and refine a previously developed risk score that predicts clinical outcomes of patients with cellulitis. Secondary objectives include investigating whether early response to antibiotic treatment (e.g. reduction in skin temperature and patient-reported symptoms) improves the predictive ability of the risk score. The study design also includes a nested technology comparison of temperature measurement devices to identify the best device for measuring affected skin temperature change in patients with cellulitis. Clinical response will be measured for up to four days from starting antibiotic treatment. This includes the change in temperature and area of affected skin, physiological observations, blood test results (e.g. C-reactive protein) and patient-reported pain and swelling scores. Patients will be followed up at 28 and 90 days (+/- 180 days for those recruited in the first year) to assess recovery, recurrence, cellulitis-related mortality, quality of life, and return to normal activities.