Nine Cases of Soft Tissue Infection Due to Non-TuberculousMycobacterium

Abstract

Background/Aims: Non-tuberculous Mycobacterium (NTM) infections usually result in chronic disease, and making a diagnosis is often difficult. Skin and soft tissue infections due to NTM are not common and are usually diagnosed relatively late. We investigated the clinical characteristics of nine cases of skin and soft tissue infections with NTM. Methods: Nine patients with an NTM infection who were confirmed consecutively by skin and soft tissue and/or adjacent bone cultures at a teaching hospital between August 2006 and July 2013 were enrolled in this study. The demographics, clinical characteristics, underlying diseases, treatment, and prognosis between different NTM species were reviewed retrospectively. Results: The most common NTM species causing a soft tissue infection was Mycobacterium abscessus (five patients, 55.6%). Common sites of infection were the knee and lumbar spine. Five patients (55.6%) had underlying diseases. Six patients (77.8%) were treated with combined surgical treatment (incision and drainage) plus antibiotics. The duration from symptom onset to diagnosis was long (77.7 ± 44.6 days) due to inadequate microbiological evaluation and disregard for the clinical significance of the NTM culture. All patients were cured with treatment; however, the treatment duration was long (181.7 ± 140.0 days). Procedure and cosmetic surgery were the most important risk factors for infection. Conclusions: The diagnosis of NTM skin and soft tissue infections tends to be delayed in a clinical setting. Therefore, a high index of suspicion for NTM infection in chronic localized soft tissue infections is essential for diagnosis. Mycobacterium abscessus appears to be the most common NTM species causing soft tissue infections. (Korean J Med 2014;87:311-317)