Prevalence And Microbiological Characteristics Of Clinically Infected Lower Extremityulcers In Patients With Rheumatoid Arthritis: A Retrospective Exploratory Study

Objective:The objective of this study was to estimate the prevalence of clinical infection in lower extremity-ulcers of patients with RA; describe the microbiological characteristics and investigate risk factors. Methods:Retrospective clinical data was collected for all patients attending a rheumatology foot ulcer clinic in the First Hospital of Shanxi Medical Univisity and Taiyuan Municipal No.2 People’s Hospital between 1st Jan 2014 and 1st Jan 2015: wound swab data was collected from those with clinical infection. Results:Twenty-eight patients with RA and lower extremity-ulcers were identified; eight of these patients had clinical infection and wound swabs taken(29 %). Of these eight patients there were equal men and women, with median age 74 years, and average disease duration 22 years. Cardiovascular disease/peripheral-vascular disease(CVD/PVD) were reported in six patients, diabetes in two patients. Six patients were treated with disease-modifying anti-rheumatic drugs(DMARDs); three were on biologic medications and two on steroids. Five wound swabs cultured skin flora, one staphylococcus aureus, one had no growth after culture; and one was rejected due to labelling error. Conclusion:Almost a third of people with RA and lower extremity ulcers attending clinic over one year had clinical infection, however microbiological analysis failed to isolate pathogens in six of seven wound swabs. This may be due to inaccurate diagnosis of ulcer infection or to issues with sampling, collection, transport, analysis or reporting. There was insufficient data to relate risk of clinical infection with risk factors. Further research is required to identify the most appropriate techniques for infection diagnosis, wound sampling and processing.