Abstract: Objective To study the characteristics of the dermatic outbreak infection caused by M.fortuitum.Methods Analyzing the clinical characteristics and therapeutic outcome of 59 cases with dermatic infection of M.fortuitum,who were admitted from January to December 1999 and confirmed by bacteriology,pathology and ultrasonic B.Results The average age of 59 cases is 32.3 years old,the ratio of male to female is 1:5.6;and average length of illness is 55±30.5 days.The 59 cases have 76 lesions92.2% of the lesions are located in the buttocks.39 case are confirmed by bacteriology accounting for 66.1% and 12 cases out of the 20 negative cases checked by bacteriology are later found positive by pathology.The total 51 positive cases account for 86.4%.All the cases are treated with the antibiotics which the bacteria are sensitive to and the antituberculotic chemotherapy which can generate cooperative effect.The cases indicated of surgery will be treated accordingly.All the cases are discharged cured.The six month follow up has seen no relapse.Conclusion The infection is caused by M.fortuitum.The therapeutic outcome is satisfactory.

Key words: M.fortuitum, Dermatic infection, Diagnosis, Treatment