Introduction Nontuberculous mycobacterial infections Epidemiology demographics often found in marine workers location hand and wrist are involved in 50% of cases risk factors immunocompromised host Pathophysiology incubation average incubation period is two weeks, but can be up to six months average time to diagnosis and appropriate treatment is more than 1 year organisms widely encountered in the environment, but rarely cause human pathology M. marinum most common atypical mycobacterium infection more common in stagnant fresh or salt water (aquariums) M kansasii found in soil M terrae found in soil M. avium intracellulare most common in terminal AIDS patients, but can occur in non-HIV patients Prognosis natural history early presentation includes papules, nodules, and ulcers late presentation may have progressed to tenosynovitis, septic arthritis, or osteomyelitis morbidity & mortality mortality rate is 32% Presentation Symptoms cutaneous rash with discomfort Physical exam papules, ulcers, and nodules are common, especially on the hands many times presents with a single nodule that may ultimately spread to the lymph nodes indistinguishable from tuberculous mycobacterial infection Studies Histology granulomas may or may not demonstrate acid-fast bacilli on AFB stain Cultures and sensitivities are key to diagnosis Lowenstein-Jensen culture agar M. marinum incubated specifically at 30 to 32° C M. avium intracellulare incubated at room temperature Treatment Nonoperative oral antibiotics indications if diagnosed at early stage medications ethambutol, tetraycline, trimethoprim-sulfamethoxazole, clarithromycin, azithromycin add rifampin if osteomyelitis present Operative surgical debridement + oral antibiotics in combination for 3 to 6 months indications later stage disease use a combination of above medications