Risk Factors for Treatment Failure in Skin and Soft Tissue Infections Caused by Nontuberculous Mycobacteria

BackgroundThis study investigated the characteristics of patients with skin and soft tissue infections (SSTIs) caused by nontuberculous mycobacteria (NTM) and identified the risk factors for treatment failure in these patients.Material and MethodsData of patients with NTM SSTIs who received treatment between January 2014 and December 2019 at Taipei Veterans General Hospital were collected retrospectively. Possible risk factors were determined using univariate and multivariate analysis with logistic regression models.ResultsA total of 47 patients (24 male, 23 female; age, 57.1 +/- 15.2 years) were enrolled. Type 2 diabetes mellitus was the most common comorbidity. The most common mycobacterial species was the Mycobacterium abscessus complex, and the most commonly affected site was the axial trunk. Treatment was successful in 38 patients (81%). Six patients had recurrent infections (13%) after the treatment course was completed, and 3 patients (6.4%) died of NTM-related infection. Delayed treatment for more than 2 months and antibiotic-alone treatment were 2 independent risk factors for treatment failure of NTM SSTIs.ConclusionsDelayed treatment for more than 2 months and antibiotic-alone treatment were associated with a higher failure rate in patients with NTM SSTIs. Therefore, the differential diagnosis of NTM infection should always be considered when the treatment course is prolonged but not effective. Early identification of causative NTM species and appropriate antibiotic treatment may lower the risk of treatment failure. Prompt surgical treatment is suggested if available.