Skin and Soft Tissue Infections in the Injection Drug Users

Introduction

Skin and soft tissue infections (SSTIs) are commonly observed among injection drug users (IDUs). The severity and extent of SSTIs in IDUs are diverse. Some patients have benign and superficial infections and some others have complex and invasive infections. The objective of this study was to retrospectively assess the epidemiologic data of IDUs admitted for SSTIs and investigate the differences between patients with superficial and invasive SSTIs.

Material and methods

We reviewed the clinical records of IDUs with SSTIs hospitalized in the Far Eastern Memorial Hospital (FEMH) from January 2005 to the end of December 2017. The patients with septic arthritis or implant related infections were excluded. We classified all patients into superficial or invasive infection group, based on clinical, radiological, and surgical findings. The patients’ demographics, underlying diseases, infection sites, laboratory and microbiological results, surgical courses, clinical outcomes and complications were collected and analyzed.

Results

Forty-seven IDU patients [36 men and 11 women, mean age, 43.6 (24–67) years] were admitted for SSTIs. There were 16 patients diagnosed with cellulitis, 3 with superficial abscess, 10 with deep abscess, 15 with necrotizing fasciitis and 3 with other necrotizing soft tissue infections. The superficial infection group comprised of 19 patients, whereas the invasive infection group comprised 28 patients. Thirteen patients had type 2 diabetes mellitus (DM) with a higher probability to have invasive infections than superficial infections (39.3% vs. 10.5%, p = 0.046). Among the invasive infection group, one patient died and three patients had vascular complications. The patients with invasive infections needed more debridements (2.46 ± 2.43 VS 0.95 ± 1.08 VS, p =0.001), skin grafts, or flaps for wound closure (28.6% VS 5.3%, p=0.06) and had longer hospital stay durations (22.8 ± 17.7 VS 12.1 ± 7.2 days, p=0.016) than the patients in the superficial infection group.

Conclusion

IDUs with diabetes mellitus showed a higher risk of invasive infections than those without DM. The patients with invasive infection required more debridements and reconstruction procedures and had a higher rate of complications. Thus, early diagnosis and timely surgical intervention can lead to positive outcomes.

Key words: skin infection, soft tissue infection, drug abuser