Abstract: Objective: To analyze the clinical features of cutaneous non-tuberculous mycobacterium (NTM) infection, to investigate the common causes, clinical features and diagnostic methods. Methods: To analyze the clinical features of 29 patients and compare the value of different methods in the diagnosis of NTM infection. Results: Of 29 patients, 8 were induced by trauma, and 6 were induced by cosmetic and injection. Nodules were the main lesions (19 cases) and 7 cases were accompanied with ulcers. There were 18 cases of single lesions and 11 cases of multiple lesions, mainly in the extremities. The histological features were mainly granulomatous inflammation (17 cases). The positivity rate of mNGS was the highest (4/4, 100%), followed by polymerase chain reaction-reverse dot blot (PCR-RDB) (13/15, 86.7%) and C-gene chip (1/5, 20%),and tissue culture was the lowest (1/12, 8%). Antibiotics were used, fifteen cases (51.7%) were cured, 4 cases (13.8%) were improved, 3 cases were ineffective, 7 cases were lost to follow-up. Conclusion: Cutaneous NTM caused by trauma, cosmetic surgery and injection can not be ignored in recent years. The histopathological changes are not specific for pathogenic bacteria. Polymerase chain react-reverse dot blot hybridization and metagenomics detection are helpful to identify the etiological of NTM.

Key words: Non-tuberculous mycobacterium, clinical manifestations, histopathology, polymerase chain reaction, genetic detection