cutaneous infections caused by atypical mycobacteria that used to be considered unusual have become frequent nowadays , particularly in immunocompromised individuals . skin and soft tissue infections caused by rapidly growing non - tuberculous mycobacteria ( ntm ) have become frequent nowadays , particularly in immunocompromised individuals . among the rapidly growing mycobacteria , mycobacterium fortuitum and mycobacterium chelonae are known for producing a wide spectrum of clinical diseases . cutaneous and subcutaneous infections by m. fortuitum are caused by colonization of the tissue following accidental trauma , injection of drugs ( cortisone ) , mesotherapy , surgical procedures , or domestic animal bites . we here report a case of chronic discharging sinus caused by m. fortuitum in a young healthy immunocompetent individual . a 16-year - old male presented to the outpatient surgery department with a pus discharging lesion over abdomen . the lesion had started as a small painful swelling 3 months back , which after a period of 1 month ulcerated to form a discharging sinus . there was history of a similar swelling in left paraumbilical region , which was incised and drained about 7 days earlier at a private clinic . on local examination , there was a 0.5 cm  0.5 cm sinus with minimal seropurulent discharge in right paraumbilical region and 1 cm  0.5 cm healing incision wound on left side [ figure 1 ] . the patient had received multiple courses of antibiotics without any improvement and had been started on antituberculous treatment ( att ) few days back . there was no history of fever , chronic cough , and loss of weight and appetite . the patient 's blood counts , sedimentation rate , and serum and urinary biochemistry were within normal limits . c - reactive protein ( crp ) level was slightly raised . discharging sinus in right and the healing incision wound in left paraumbilical region the sinus discharge was collected and subjected to microbiological evaluation that included gram stain , ziehl  neelsen ( zn ) stain , and stains to detect fungi . the specimen was cultured on to blood agar ( hi media , mumbai , india ) and macconkey agar ( hi media , mumbai , india ) for aerobic and anaerobic bacteria , lowenstein jensen ( lj ) ( hi media , mumbai , india ) medium for mycobacteria and sabouraud 's dextrose agar ( hi media , mumbai , india ) for fungal isolation . zn stain revealed acid fast bacilli ( afb ) while other stains did not show any microorganism . cultures for bacteria and fungi were negative . however , magenta colored colonies appeared on macconkey agar after 48 h of incubation and small white colonies grew on the lj media after 5 days of incubation . the isolate was identified as m. fortuitum based on growth on macconkey agar , non - photochromogenic colonies , positive nitrate reduction , iron uptake , aryl sulfatase , tolerance to 5% nacl and 68c catalase . the isolate was subjected to minimum inhibitory concentration ( mic ) testing by mycobacterium growth indicator tube mgit 960 and was found to be sensitive to amikacin ( mic < 1 g / ml ) , ofloxacin ( mic < 2 g / ml ) , and capreomycin ( mic < 2.5 g / ml ) and resistant to rifampicin ( mic > 1 g / ml ) , isoniazid ( mic > 0.1 g / ml ) , ethambutol ( mic > 5 g / ml ) , streptomycin ( mic > 1 g / ml ) , and kanamycin ( mic > 1 g / ml ) . the patient was advised to discontinue att and was started on a course of amikacin ( 15 mg / kg intramuscular daily for 1 month ) and ofloxacin ( 400 mg oral daily for 4 months ) therapy . the lesion healed completely after 4 months of therapy with no recurrence after 6 months follow - up . , m. fortuitum mainly causes infections of the skin , lungs , lymph nodes , and joints . in the skin the lesions tend to be subacute or chronic , occult , resistant to treatment , and recurrent . cutaneous disease with environmental mycobacteria follows two patterns : following trauma ( accidental or surgical ) in immunocompetent patients , a single abscessed lesion appears in the damaged region 4 - 6 weeks later and heals spontaneously in 20 - 30% of patients . however , immunocompromised patients develop disseminated , multiple subcutaneous nodules and usually no previous trauma is described . the histological findings due to rapidly - growing mycobacteria are varied , depending on the immune status of the patient and the amount of time the lesions have been developing . thus the chance of overlooking these organisms is high unless microbiological confirmation is done . there are multiple reports of m. fortuitum infection after trauma and surgical procedures , liposuction , pedicure , and subcutaneous injections . isolation of m. fortuitum from soft tissue infections in immunocompetent individuals have also been reported . they are particularly sensitive to amikacin and also to the tetracyclines , first generation cephalosporins , quinolones , and the new macrolides . our case is unusual because the patient was an immunocompetent young male with chronic sinus formation . the source of infection could not be traced . at the time of presentation , single sinus was present . unfortunately , the swelling on the other side had already been debrided and thus could not be diagnosed . hence , a high degree of clinical suspicion followed by microbiological identification and susceptibility testing allows the timely and efficient therapy of such patients . immunocompetent individuals are also prone to atypical mycobacteria , hence , every specimen received for pyogenic culture must be processed for afb examination and culture also .
cutaneous infections caused by atypical mycobacteria are uncommon and the diagnosis can be missed unless there is strong clinical suspicion supported by laboratory confirmation . 
 we report a case of chronic discharging sinus caused by mycobacterium fortuitum in a young healthy immunocompetent individual . 
 the patient recovered completely following amikacin and ofloxacin therapy .