Mycobacterium chelonae: a cause of nodular skin lesions with a proclivity for renal transplant recipients.

Infections due to Mycobacterium chelonae are uncommon. Several renal transplant recipients at our medical center have developed M. chelonae infections during the past several years, so we decided to review our recent experience with M. chelonae infections. The clinical microbiology laboratory records of four Vanderbilt University Affiliated Hospitals were reviewed. Ten patients with M. chelonae tissue or blood infections were identified between 1982 and July 1988. All infections involved the skin and subcutaneous tissue. Three infections developed at the sites of medical injections. The remaining seven infections occurred in renal transplant recipients and produced a clinically distinctive syndrome. All were indolent tender nodular lesions on the extremities, usually the lower legs. Systemic symptoms were absent, and white blood cell counts were within normal limits. Diagnosis required tissue biopsy and cultures that were incubated for a month. Therapy consisted of surgical excision combined with long-term antibiotics. Even so, some patients had a chronic, relapsing course. Although other diagnoses must be considered, the presumptive diagnosis of M. chelonae infection is suggested by the appearance of nodular erythematous lesions on the legs of a renal transplant recipient.