Characteristics of skin and soft tissue infection caused by non-tuberculous mycobacteria in Taiwan.

SETTING

A medical centre in Taipei, Taiwan.

OBJECTIVE

To investigate the clinicopathological and microbiological correlates of skin and soft tissue infection (SSTI) due to non-tuberculous mycobacteria (NTM).

DESIGN

Patients with NTM SSTI identified from 1999 to 2009 were included. Histological sections of the skin biopsy specimens from these patients were reassessed.

RESULTS

Among 58 patients with NTM SSTI, the most commonly isolated NTM were rapidly growing mycobacteria (RGM; n = 30), Mycobacterium marinum (n = 17) and M. avium complex (MAC) (n = 4). Twenty-nine (50%) of the NTM SSTI involved deep soft tissue; these progressed to local tenosynovitis in 20 patients. All of the cutaneous lesions infected with M. marinum occurred on the upper extremities; in 9 patients the skin eruptions developed after injury in an aquatic environment. Skin lesions with RGM infection usually occurred on the lower extremities, and in 6 patients the infection developed from wounds caused by medical procedures. Granulomatous inflammation with fibrinoid necrosis was present in 47% of lesions in patients with M. marinum infection and suppurative granulomatous inflammation was noted in 45% of patients with RGM infection.

CONCLUSIONS

Identification of a close clinicopathological correlate is useful for dermatologists and pathologists in the early diagnosis and treatment of NTM SSTI.