Successful Treatment of Cutaneous Mycobacterium chelonae Infection in an Immunocompromised Patient Using Moxifloxacin and Clarithromycin

<i>Mycobacterium chelonae</i> is a ubiquitous organism classified as a nontuberculous mycobacterium that rarely causes indolent skin or soft-tissue infections, especially in immunocompromised patients. Given the rarity of <i>M. chelonae</i> infection, diagnosis can be difficult because cutaneous lesions may be considered a worsening of the underlying disease or a benign condition. Here, we report a case of a rapidly progressing cutaneous <i>M. chelonae</i> infection in a patient with nephrotic syndrome. The cutaneous lesion was initially stable for five months, mimicking noninfectious etiologies; however, due to rapid worsening, prompt skin biopsy revealed <i>M. chelonae</i> infection. Clinicians should be aware of this unusual presentation of <i>M. chelonae</i> infection and have a low threshold for performing biopsies for the early diagnosis and prevention of disease progression. The patient was successfully treated using a combination of moxifloxacin and clarithromycin. The choices of antibiotics and duration of treatment for nontuberculous mycobacterial infections are not clearly determined and depend on the clinician's experience. As treatment duration is prolonged, it sometimes carries the risk of developing drug resistance. We also evaluated the efficacy of moxifloxacin and clarithromycin for treating cutaneous <i>M. chelonae</i> infections in immunocompromised patients who require long-term antibiotic therapy.